SEMICONDUCTOR LASER ELEMENT

Abstract

A semiconductor laser element comprises: an n-doped cladding layer (402); one or more n-sided guide layers provided above the n-doped cladding layer (402); an active layer (405) provided above the one or more n-sided guide layers; a p-sided semiconductor layer (400p) provided above the active layer (405); and a p-sided electrode (113) provided above and in ohmic contact with the p-sided semiconductor layer (400p). The active layer (405) comprises one or more pot layers.A second distance between the p-side electrode (113) and a pot layer (405b) from the one or more pot layers closest to the p-side electrode (113) is shorter than a first distance between the n-doped shell layer (402) and a pot layer (405b) from the one or more pot layers closest to the n-doped shell layer (402). The p-side electrode (113) contains at least one of Ag, Al, or Rh.

Description

[Technical field] The present disclosure relates to a semiconductor laser element. [State of the art] A light-emitting semiconductor element is typically used as a light source, for example, in a processing device. There is a need for a processing device light source that delivers higher power and higher efficiency. To increase the efficiency of a semiconductor laser element, a technology for lowering the operating voltage is known, for example (see, for example, patent literature (PTL) 1). [List of quotes] [Patent literature] [PTL 1] Japanese unexamined patent application Publication No. 2014-131019 [Summary of the invention] [Technical problem] It is effective to reduce the thickness of a p-doped cladding layer between a p-side electrode and an active layer to lower the operating voltage in a semiconductor laser element. However, when the thickness of the p-doped cladding layer is reduced, the distance between the p-side electrode and the active layer decreases, and thus light generated and amplified in the active layer penetrates more easily into the p-side electrode. Consequently, light loss due to absorption in the p-side electrode increases. The present disclosure addresses such problems and provides a semiconductor laser element that can lower the operating voltage and reduce light loss. [Problem solving] To address such problems, a semiconductor laser element according to a first aspect of the present disclosure comprises: an n-doped cladding layer; one or more n-sided guide layers provided above the n-doped cladding layer; an active layer provided above the one or more n-sided guide layers; a p-sided semiconductor layer provided above the active layer; and a p-sided electrode provided above the p-sided semiconductor layer and in ohmic contact with the p-sided semiconductor layer.The active layer includes one or more pot layers, a second distance between the p-side electrode and a pot layer nearest to the one or more pot layers of the p-side electrode is shorter than a first distance between the n-doped shell layer and a pot layer nearest to the one or more pot layers of the n-doped shell layer, and the p-side electrode contains at least one of Ag, Al or Rh. To address such problems, a semiconductor laser element according to a second aspect of the present disclosure comprises: an n-doped cladding layer; one or more n-sided guide layers provided above the n-doped cladding layer; an active layer provided above the one or more n-sided guide layers; one or more p-sided guide layers provided above the active layer; a p-sided semiconductor outer layer provided above the one or more p-sided guide layers and in contact with the one or more p-sided guide layers; and a p-sided electrode provided above the p-sided semiconductor outer layer and in ohmic contact with the p-sided semiconductor outer layer.The p-side semiconductor outer layer has a thickness less than the thickness from a p-side guide layer closest to the active layer to a p-side guide layer furthest from the active layer of one or more p-side guide layers, and the p-side electrode contains at least one of Ag, Al, or Rh. To address such problems, a semiconductor laser element according to a third aspect of the present disclosure comprises: an n-doped cladding layer; one or more n-sided guide layers provided above the n-doped cladding layer; an active layer provided above the one or more n-sided guide layers; one or more p-sided guide layers provided above the active layer; a p-sided semiconductor outer layer provided above the one or more p-sided guide layers and in contact with the one or more p-sided guide layers; and a p-sided electrode provided above the p-sided semiconductor outer layer and in ohmic contact with the p-sided semiconductor outer layer.The active layer includes one or more pot layers, the p-side semiconductor outer layer has a thickness less than a first distance between the n-doped cladding layer and a pot layer that is closest to the one or more pot layers of the n-doped cladding layer, and the p-side electrode contains at least one of Ag, Al or Rh. [Advantageous effects of the invention] According to the present disclosure, a semiconductor laser element can be provided which can lower the operating voltage and reduce light loss. [Brief description of the drawings] [Fig. 1] Fig. 1 is a schematic top view illustrating an overall configuration of a semiconductor laser element according to embodiment 1. [Fig. 2A] Fig. 2A is a schematic cross-sectional view illustrating an overall configuration of the semiconductor laser element according to embodiment 1. [Fig. 2B] Fig. 2B is a schematic cross-sectional view illustrating an active layer configuration included in the semiconductor laser element according to embodiment 1. [Fig. 3] Fig. 3 is a diagram showing configurations of layers, different from a substrate, included in a semiconductor stack body according to embodiment 1. [Fig. 4] Fig. 4 is a schematic cross-sectional view illustrating an overall configuration of a semiconductor laser element according to embodiment 2. [Fig. 5] Fig.Figure 5 is a schematic diagram showing a distribution of bandgap energy in an active layer and layers in its vicinity in the semiconductor laser element according to embodiment 2. [Fig. 6] Figure 6 is a diagram showing configurations of layers, different from a substrate, included in a semiconductor stack body according to embodiment 2. [Fig. 7] Figure 7 is a schematic cross-sectional view illustrating an overall configuration of a semiconductor laser element according to embodiment 3. [Fig. 8] Figure 8 is a schematic cross-sectional view illustrating an overall configuration of a semiconductor laser element according to embodiment 4. [Fig. 9] Figure 9 is a schematic diagram illustrating a distribution of bandgap energy in an active layer and layers in its vicinity in a semiconductor laser element according to embodiment 4. [Fig. 10]Figure 10 is a diagram showing configurations of layers, different from a substrate, contained in a semiconductor stack body according to embodiment 4. [Figure 11] Figure 11 is a schematic cross-sectional view illustrating an overall configuration of a semiconductor laser element according to embodiment 5. [Figure 12] Figure 12 is a schematic cross-sectional view illustrating an overall configuration of a semiconductor laser element according to embodiment 6. [Figure 13] Figure 13 is a schematic diagram showing a distribution of bandgap energy in an active layer and layers in its vicinity in the semiconductor laser element according to embodiment 6. [Figure 14] Figure 14 is a schematic cross-sectional view illustrating an overall configuration of a semiconductor laser element according to embodiment 7. [Figure 15]Figure 15 is a schematic cross-sectional view illustrating an overall configuration of a semiconductor laser element according to embodiment 8. [Fig. 16] Figure 16 is a schematic cross-sectional view illustrating a configuration of a hole-blocking layer of the semiconductor laser element according to embodiment 8. [Fig. 17] Figure 17 is a schematic cross-sectional view illustrating a configuration of an active layer of the semiconductor laser element according to embodiment 8. [Fig. 18] Figure 18 is a first diagram illustrating configurations of layers that differ from a substrate and are included in a semiconductor stack body according to one embodiment. [Fig. 19] Figure 19 is a second diagram illustrating configurations of layers that differ from the substrate and are included in the semiconductor stack body according to the embodiment. [Fig. 20]Figure 20 is a schematic cross-sectional view illustrating an overall configuration of a semiconductor laser element according to embodiment 9. [Description of embodiments] Embodiments of the present disclosure are described below with reference to the drawings. It should be noted that the embodiments described below each represent a specific example of the present disclosure. Accordingly, the numerical values, shapes, materials, elements, arrangement and connection of the elements, and other features mentioned in the following embodiments are only examples and are not intended to limit the present disclosure. The drawings are schematic diagrams and do not necessarily provide an exact illustration. Therefore, for example, scales are not necessarily the same throughout all drawings. In the drawings, the same element is essentially labeled with the same reference symbol, and its redundant description can be omitted or simplified. In this description, the terms "above" and "below" do not refer to vertically upwards and downwards in absolute spatial perception, but rather are used as terms defined by a relative positional relationship based on the sequence of stacked layers in a stacked configuration. Furthermore, the terms "above" and "below" are used not only when two elements are spaced apart with another element between them, but also when two elements are in contact with each other. In the present description, a term that indicates a relationship between elements, such as identical, and a range of numbers do not necessarily have only strict meanings and are expressions that essentially cover equivalent ranges, including a difference of about a few percent, for example. [Version 1] A semiconductor laser element according to embodiment 1 is described. [1-1. Overall configuration] First, an overall configuration of the semiconductor laser element according to the present embodiment is described with reference to Fig. 1, Fig. 2A, Fig. 2B, and Fig. 3. Fig. 1 and Fig. 2A are a schematic top view and a schematic cross-sectional view, respectively, illustrating the overall configuration of semiconductor laser element 100 according to the present embodiment. Fig. 2B is a schematic cross-sectional view illustrating a configuration of active layer 105 incorporated in semiconductor laser element 100 according to the present embodiment. Fig. 2A and Fig. 2B show cross-sections along line II-II in Fig. 1. It should be noted that the drawings show the X-axis, Y-axis, and Z-axis orthogonal to each other. The X-axis, Y-axis, and Z-axis form a right-handed orthogonal coordinate system.One stacking direction of semiconductor laser element 100 is parallel to the Z-axis direction, and a principal direction in which light (laser beam) is emitted is parallel to the Y-axis direction. Fig. 3 is a diagram showing configurations of layers, different from substrate 101, that are incorporated in semiconductor stack bodies 100S according to the present embodiment. As illustrated in Fig. 2A, semiconductor laser element 100 includes a semiconductor stack body 100S, which contains stacked semiconductor layers and emits light from the end face 100F (see Fig. 1) in a direction perpendicular to the stacking direction of semiconductor stack body 100S (i.e., the Z-axis direction). In the present embodiment, semiconductor laser element 100 is a nitride-based semiconductor laser element comprising two end faces 100F and 100R, which form a resonator. End face 100F is a front end face from which a laser beam is emitted, and end face 100R is a rear end face with a higher reflectance than end face 100F. In the present embodiment, the reflectance of end face 100F and the reflectance of end face 100R are 16% and 95%, respectively.The length of the resonator (i.e., a distance between end face 100F and end face 100R) of semiconductor laser element 100 according to the present embodiment is approximately 1200 µm. As illustrated in Fig. 2A, semiconductor laser element 100 comprises a semiconductor stack body 100S, current-blocking layer 112, p-side electrode 113 and n-side electrode 114. Semiconductor stack body 100S comprises substrate 101, n-doped cladding layer 102, one or more n-side guide layers, active layer 105 and p-side semiconductor layer 100p. The one or more n-sided guide layers are semiconductor layers provided over an n-doped cladding layer 102. The average refractive index of each of the one or more n-sided guide layers is lower than the average refractive index of active layer 105 and higher than the average refractive index of the n-doped cladding layer 102. The average bandgap energy of each of the one or more n-sided guide layers is greater than the average bandgap energy of active layer 105 and less than the average bandgap energy of the n-doped cladding layer 102. In the present embodiment, the semiconductor laser element 100 comprises a first n-sided guide layer 103 and a second n-sided guide layer 104 as the one or more n-sided guide layers. It should be noted that in the present disclosure, the average refractive index of each layer refers to the value of the refractive index obtained by integrating the orders of magnitude of refractive indices at positions in the stacking direction of this layer from the position of the interface on the side near substrate 101 to the position of the interface on the side far from substrate 101 in the stacking direction of the layer and dividing the resulting value by the thickness of this layer (the distance between the interface on the side near substrate 101 and the interface on the side far from substrate 101). It should be noted that in the present disclosure, the average band gap energy of each layer refers to the value of the band gap energy obtained by integrating the orders of magnitude of the band gap energy at positions in the stacking direction of this layer from the position of the interface on the side near substrate 101 to the position of the interface on the side far from substrate 101 in the stacking direction of the layer and dividing the resulting value by the thickness of this layer (the distance between the interface on the side near substrate 101 and the interface on the side far from substrate 101). The p-side semiconductor layer 100p includes one or more p-side guide layers and a p-side semiconductor outer layer 100u. The one or more p-sided guide layers are semiconductor layers provided above active layer 105. In semiconductor laser element 100, which includes p-doped cladding layer 110, the one or more p-sided guide layers are provided below p-doped cladding layer 110. The average refractive index of each of the one or more p-sided guide layers is lower than the average refractive index of active layer 105 and higher than the average refractive index of n-doped cladding layer 102. The average bandgap energy of each of the one or more p-sided guide layers is greater than the average bandgap energy of active layer 105 and less than the average bandgap energy of n-doped cladding layer 102.In the present embodiment, semiconductor laser element 100 comprises first p-sided guide layer 106, second p-sided guide layer 107 and third p-sided guide layer 108 as the one or more p-sided guide layers. The p-side semiconductor outer layer 100u is a semiconductor layer provided above and in contact with one or more p-side guide layers. In the present embodiment, the p-side semiconductor outer layer 100u comprises an electron-blocking layer 109, a p-doped cladding layer 110, and a p-doped contact layer 111. Substrate 101 is a plate-shaped element that serves as the basis for semiconductor laser element 100. In the present embodiment, substrate 101 is an n-type GaN substrate. N-doped cladding layer 102 is an n-doped semiconductor layer provided via substrate 101. N-doped cladding layer 102 has a lower average refractive index and a higher average bandgap energy than active layer 105. In the present embodiment, n-doped cladding layer 102 is an n-doped Al0.035Ga0.965N layer with a thickness of 1200 nm, as illustrated in Fig. 3. N-doped cladding layer 102 is doped with Si as an impurity at an average concentration of 1 × 10¹⁸ cm⁻³. In the present disclosure, the average concentration of an impurity in each layer (that is, the average impurity concentration) refers to the value of the impurity concentration obtained by integrating the orders of magnitude of the impurity concentrations at positions in the stacking direction of this layer from the position of the interface on the side near substrate 101 to the position of the interface on the side farther from substrate 101 in the stacking direction of the layer, and dividing the resulting value by the thickness of this layer (the distance between the interface on the side near substrate 101 and the interface on the side farther from substrate 101). Impurities refer to dopants added to achieve n-doped conductivity in n-doped semiconductor layers and dopants added to achieve p-doped conductivity in p-doped semiconductor layers. The first n-sided guide layer 103 is an example of one or more n-sided guide layers provided over an n-doped cladding layer 102. In the present embodiment, the first n-sided guide layer 103 is an n-doped GaN layer with a thickness of 100 nm. The first n-sided guide layer 103 is doped with Si as a defect at an average concentration of 1 × 10¹⁸ cm⁻³. The second n-sided guide layer 104 is an example of one or more n-sided guide layers provided above an n-doped cladding layer 102. The second n-sided guide layer 104 is provided above the first n-sided guide layer 103. In the present embodiment, the second n-sided guide layer 104 is an undoped In0.03Ga0.97N layer with a thickness of 150 nm. Active layer 105 is a light-emitting layer provided above one or more n-sided guide layers. In the present embodiment, active layer 105 is provided above a second n-sided guide layer 104. Active layer 105 comprises one or more pot layers and a plurality of barrier layers. Active layer 105 includes pot layers 105b and 105d and barrier layers 105a, 105c, and 105e, as illustrated in Fig. 2B. It should be noted that active layer 105 can have a single quantum pot structure or a multiple quantum pot structure with three or more pot layers. In the present embodiment, active layer 105 emits blue light of about 450 nm. Barrier layer 105a is provided above a second n-sided guide layer 104 and serves as a barrier to the quantum well structure. In the present embodiment, barrier layer 105a is an undoped In0.04Ga0.96N layer with a thickness of 6 nm. Pot layer 105b is provided above barrier layer 105a and serves as a pot of the quantum well structure. Pot layer 105b is provided between barrier layer 105a and barrier layer 105c. In the present embodiment, pot layer 105b is an undoped In0.18Ga0.82N layer with a thickness of 3 nm. Barrier layer 105c is provided via pot layer 105b and serves as a barrier to the quantum well structure. In the present embodiment, barrier layer 105c is an undoped In0.04Ga0.96N layer with a thickness of 7 nm. Pot layer 105d is provided above barrier layer 105c and serves as a pot of the quantum well structure. Pot layer 105d is provided between barrier layer 105c and barrier layer 105e. In the present embodiment, pot layer 105d is an undoped In0.18Ga0.82N layer with a thickness of 3 nm. Barrier layer 105e is provided via pot layer 105d and serves as a barrier to the quantum well structure. In the present embodiment, barrier layer 105e is an undoped In0.04Ga0.96N layer with a thickness of 6 nm. The first p-sided guide layer 106 is an example of one or more p-sided guide layers provided above active layer 105. Furthermore, the first p-sided guide layer 106 is an example of an inner guide layer provided by the one or more p-sided guide layers at the position closest to active layer 105. In the present embodiment, the first p-sided guide layer 106 is an undoped In0.03Ga0.97N layer with a thickness of 100 nm. The second p-sided guide layer 107 is an example of the one or more p-sided guide layers provided above the active layer 105. The second p-sided guide layer 107 is provided above the first p-sided guide layer 106. In the present embodiment, the second p-sided guide layer 107 is an undoped In0.01Ga0.99N layer with a thickness of 190 nm. Third p-sided guide layer 108 is an example of one or more p-sided guide layers provided above active layer 105. Furthermore, third p-sided guide layer 108 is an example of an outer guide layer provided by one or more p-sided guide layers at the position closest to p-sided electrode 113. Third p-sided guide layer 108 is provided above second p-sided guide layer 107.The average refractive index of the third p-sided guide layer 108 is lower than the average refractive index of active layer 105 and higher than the average refractive index of p-doped cladding layer 110. The average bandgap energy of the third p-sided guide layer 108 is greater than the average bandgap energy of active layer 105 and less than the average bandgap energy of p-doped cladding layer 110. In the present embodiment, the third p-sided guide layer 108 is provided between the second p-sided guide layer 107 and the electron blocking layer 109. The third p-sided guide layer 108 has a function for reducing a voltage generated due to a difference in lattice constant between the second p-sided guide layer 107 and the electron blocking layer 109.Accordingly, the occurrence of crystal defects in the semiconductor laser element 100 can be prevented. In the present embodiment, the third p-sided guide layer 108 is an undoped GaN layer with a thickness of 20 nm. Electron-blocking layer 109 is a semiconductor layer provided above active layer 105 and acts as a barrier to electrons. In the present embodiment, electron-blocking layer 109 is a semiconductor layer containing at least Al. Electron-blocking layer 109 is provided between the third p-sided guide layer 108 and the p-doped cladding layer 110. Electron-blocking layer 109 is a p-doped AlGaN layer with a thickness of 5 nm. Electron-blocking layer 109 includes an Al composition ratio gradient region in which the Al composition ratio monotonically increases with decreasing distance from the p-doped cladding layer 110. Here, the configuration in which the Al composition ratio monotonically increases includes a region where the Al composition ratio is constant in the stacking direction.For example, the configuration in which the Al composition ratio increases monotonically also includes a configuration in which the Al composition ratio increases stepwise. In electron-blocking layer 109 according to the present embodiment, the entire electron-blocking layer 109 is an Al composition ratio increase region and has an Al composition ratio that increases at a constant rate of change in the stacking direction. In particular, electron-blocking layer 109 has a composition specified by Al0.02Ga0.98N at and near its interface with the third p-sided guide layer 108. The Al composition ratio of electron-blocking layer 109 increases monotonically with decreasing distance from the p-doped shell layer 110.Electron-blocking layer 109 has a composition specified as Al0.36Ga0.64N at and near its interface with p-doped shell layer 110. Electron-blocking layer 109 is doped with Mg at an average concentration of 1 × 10¹⁹ cm⁻³ as an impurity. Electron blocking layer 109 can prevent electron leakage from active layer 105 to p-doped cladding layer 110. Furthermore, electron blocking layer 109 has an Al composition change region where the Al composition ratio increases monotonically. This reduces the potential barrier in a valence band of electron blocking layer 109 compared to cases where the Al composition ratio is uniform. Consequently, holes flow easily from the p-doped cladding layer 110 to the active layer 105. Thus, as in the present embodiment, an increase in the electrical resistance of the semiconductor laser element 100 can be prevented, even if the total thickness of the first p-sided guide layer 106 and the second p-sided guide layer 107, which are undoped layers, is large. Therefore, the operating voltage of the semiconductor laser element 100 can be reduced.Since the self-heating of semiconductor laser element 100 during operation can be reduced, the temperature characteristics of semiconductor laser element 100 can be improved. Thus, semiconductor laser element 100 can operate at high power. A p-doped cladding layer 110 is provided above an active layer 105. In the present embodiment, the p-doped cladding layer 110 is provided between an electron-blocking layer 109 and a p-doped contact layer 111. The p-doped cladding layer 110 has a lower average refractive index and a higher average bandgap energy than the active layer 105. The average refractive index of the p-doped cladding layer 110 is lower than the average refractive index of each of the one or more p-sided guide layers. The average bandgap energy of the p-doped cladding layer 110 is higher than the average bandgap energy of each of the one or more p-sided guide layers. Accordingly, the electrical resistance of the semiconductor laser element 100 can be reduced. Thus, the operating voltage of the semiconductor laser element 100 can be lowered.Since the self-heating of the semiconductor laser element 100 during operation can be reduced, its temperature characteristics can be improved. This allows the semiconductor laser element 100 to operate at high power. In the present embodiment, the p-doped cladding layer 110 is a p-doped Al0.035Ga0.965N layer with a thickness of 100 nm and doped with Mg at an average concentration of 2 × 10¹⁸ cm⁻³. The impurity concentration at an edge of the p-doped cladding layer 110 on the side near the active layer 10⁵ can be lower than the impurity concentration at an edge of the p-doped cladding layer 110 on the side farther from the active layer 10⁵. The p-doped contact layer 111 is provided via the p-doped cladding layer 110 and is in ohmic contact with the p-side electrode 113. In the present embodiment, the p-doped contact layer 111 is a p-doped GaN layer with a thickness of 100 nm. The p-doped contact layer 111 is doped with Mg at an average concentration of 1 × 10²⁰ cm⁻³ as an impurity. Bridge 110R is provided in p-doped cladding layer 110 and p-doped contact layer 111 in the semiconductor stack body 100S. Bridge 110R is a portion that projects upwards from the lower surface 110Tb and extends in the Y-axis direction. Bridge 110R comprises upper surface 110Rt and side surfaces 110Rs. Side surface 110Rs is a surface that connects the upper surface 110Rt and the lower surface 110Tb of bridge 110R. Side surface 110Rs is in contact with the lower surface 110Tb at the bottom edge 110Rb of the bridge. In the present embodiment, two projecting parts 110P are provided in the p-doped cladding layer 110 and the p-doped contact layer 111 of a semiconductor stack body 100S. The two projecting parts 110P extend upwards from a lower surface 110Tb and in the Y-axis direction. A web 110R is provided between the two projecting parts 110P. Each of the two projecting parts 110P comprises a top surface 110Pt and a side surface 110Ps. A groove 110T is provided between each of the two projecting parts 110P and the web 110R. Grooves 110T are provided along the web 110R and extend in the Y-axis direction. Lateral surface 110Ps is a surface that connects upper surface 110Pt and lower surface 110Tb from the surfaces of the projecting part 110P.In the present embodiment, the position in the stacking direction of upper surface 110Pt of each projecting part 110P is the same as the position in the stacking direction of upper surface 110Rt of web 110R. In the present embodiment, the web width W is approximately 30 µm. The lower surface 110Tb and the lower edge of the web 110Rb are located between the uppermost and lowermost surfaces of the p-doped cladding layer 110 in the stacking direction. In the present embodiment, the lower surface 110Tb and the lower edge of the web 110Rb are located 50 nm below the uppermost surface of the p-doped cladding layer 110. Current-blocking layer 112 is an insulating layer provided over p-side semiconductor layer 100p. In the present embodiment, current-blocking layer 112 has a transmittance with respect to light from active layer 105. As illustrated in Fig. 2A, current-blocking layer 112 is provided in regions of the upper surface of semiconductor stack body 100S that are not the upper surface 110Rt of web 110R. In particular, current-blocking layer 112 is provided continuously over lateral surfaces 110Rs of web 110R, lower surface 110Tb, lateral surfaces 110Ps of projecting parts 110P, each on the side closer to web 110R, and upper surfaces 110Pt of projecting parts 110P. In the present embodiment, current-blocking layer 112 is a SiO2 layer. The p-side electrode 113 is a conductive layer provided above the p-side semiconductor layer 100p and in ohmic contact with the p-side semiconductor layer 100p. In the present embodiment, the p-side electrode 113 is in ohmic contact with the p-side semiconductor outer layer 100u. As illustrated in Fig. 2A, the p-side electrode 113 is provided above the upper surface 110Rt of the bridge 110R of the p-doped contact layer 111 and also above the lateral surfaces 110Rs of the bridge 110R, the lower surface 110Tb, the lateral surfaces 110Ps of projecting parts 110P (each on the side closer to the bridge 110R), and the upper surfaces 110Pt of projecting parts 110P, via a current-blocking layer 112. The P-side electrode 113 contains at least one of Ag, Al or Rh.Thus, p-side electrode 113 can be a single-layer film containing at least one of Ag, Al, or Rh, or it can be a multi-layer film including a layer containing at least one of Ag, Al, or Rh. The multi-layer film including a layer containing at least one of Ag, Al, or Rh can be a multi-layer film including a layer containing at least one of Ag, Al, or Rh and a conductive layer containing none of Ag, Al, or Rh. The layer containing at least one of Ag, Al, or Rh can be a layer consisting essentially of Ag, Al, or Rh, or it can be a layer consisting essentially of an alloy containing at least one of Ag, Al, or Rh. The reflectance of p-side electrode 113 for light emitted by active layer 105 can be 80% or higher.In the present embodiment, the p-side electrode 113 comprises a layer 150 nm thick, consisting essentially of Ag or an alloy containing Ag, and a Pt layer 100 nm thick, which is provided above this layer. It should be noted that the configuration of the p-side electrode 113 is not limited here and it may contain at least one of Ag, Al, or Rh. For example, the p-side electrode 113 may be: an Ag layer 100 nm thick; a layered film of an Ag layer 50 nm thick and an Rh layer 50 nm thick; a layered film of an Ag layer 50 nm thick and an Al layer 50 nm thick; an Rh layer 100 nm thick; or an Al layer 100 nm thick.Furthermore, the p-side electrode 113 can contain a metal layer exhibiting favorable ohmic properties and being thinner than a layer containing at least one of Ag, Al, or Rh, and is provided between a layer containing at least one of Ag, Al, or Rh and the p-doped contact layer 111. As such, a metal layer exhibiting favorable ohmic properties, for example, a Pd layer, a Ni layer, a Pt layer, or the like, can be used. The N-side electrode 114 is a conductive layer provided beneath substrate 101 (that is, beneath a major surface of substrate 101 opposite the major surface above which semiconductor stack body 100S is provided). The N-side electrode 114 is a single-layer film or a multi-layer film provided using, for example, at least one of Cr, Ti, Ni, Pd, Pt, or Au. [1-2. Effects] The effects of a semiconductor laser element 100 according to the present embodiment are described. In a semiconductor laser element 100 according to the present embodiment, the thickness of the p-side semiconductor outer layer 100u beneath one or more pot layers included in the active layer 105 is less than a first distance between the pot layer 105b, which is closest to the n-doped cladding layer 102, and the n-doped cladding layer 102 and the p-side electrode 113, which contains at least one of Ag, Al, or Rh. In the present embodiment, the first distance is equal to the total thickness of the first n-side guide layer 103, the second n-side guide layer 104, and the barrier layer 105a.When bridge 110R is provided in p-doped cladding layer 110, the thickness of p-side semiconductor outer layer 100u represents the total thickness of electron blocking layer 109, p-doped cladding layer 110 and p-doped contact layer 111 in the region containing bridge 110R (that is, the position in the X-axis direction in the region where bridge 110R is provided). As described above, in semiconductor laser element 100 according to the present embodiment, since the thickness of the p-side semiconductor outer layer 100u is less than the first spacing, the thickness of a semiconductor layer with electrical resistance can be reduced, and thus the electrical resistance in the p-side semiconductor outer layer 100u can be reduced. Therefore, the operating voltage of semiconductor laser element 100 can be lowered. Furthermore, if the thickness of the p-side semiconductor outer layer 100u is small, as described above, light generated and amplified in the active layer readily penetrates the p-side electrode 113. However, in the semiconductor laser element 100 according to the present embodiment, the refractive index of the p-side electrode 113 can be reduced and its reflectivity increased by the p-side electrode 113 containing at least one of Ag, Al, or Rh. This prevents light penetration into the p-side electrode 113 and reduces light loss. Moreover, because the reflectivity of the p-side electrode 113 is high, some of the light spontaneously emitted by the active layer 105 and incident on the p-side electrode 113 is reflected by the p-side electrode 113 and returns to the active layer 105.Accordingly, active layer 105 can be optically excited, thus increasing the ratio of light output to input power of semiconductor laser element 100. This, in turn, increases the power utilization efficiency of semiconductor laser element 100. In the semiconductor laser element 100 according to the present embodiment, the total thickness of one or more p-sided guide layers can be greater than the total thickness of one or more n-sided guide layers. Thus, the total thickness of the first p-sided guide layer 106, the second p-sided guide layer 107, and the third p-sided guide layer 108 can be greater than the total thickness of the first n-sided guide layer 103 and the second n-sided guide layer 104. Accordingly, in comparison to the case where the total thickness of the first p-sided guide layer 106, the second p-sided guide layer 107, and the third p-sided guide layer 108 is less than or equal to the thickness of the second n-sided guide layer 104, the luminous intensity distribution can be shifted in the direction from the active layer 105 to the first p-sided guide layer 106. Thus, it is possible to prevent the shift of the peak of the luminous intensity distribution in the stacking direction from the active layer 105 to the first n-sided guide layer 103 due to a reduction in the second spacing. In semiconductor laser element 100 according to the present embodiment, the p-sided semiconductor layer 100p can include one or more p-sided guide layers and a p-sided semiconductor outer layer 100u, which is provided above the one or more p-sided guide layers and in contact with the one or more p-sided guide layers. Accordingly, light can be confined to one or more p-sided guide layers by making the average refractive index of such a p-sided semiconductor outer layer 100u lower than that of the one or more p-sided guide layers. The semiconductor laser element 100 according to the present embodiment comprises: an n-doped cladding layer 102; one or more n-sided guide layers provided above the n-doped cladding layer 102; an active layer 105 provided above the one or more n-sided guide layers; one or more p-sided guide layers provided above the active layer 105; a p-sided semiconductor outer layer 100u provided above the one or more p-sided guide layers and in contact with the one or more p-sided guide layers; and a p-sided electrode 113 provided above the p-sided semiconductor outer layer 100u and in ohmic contact with the p-sided semiconductor outer layer 100u.The p-side semiconductor outer layer 100u has a thickness less than the thickness from the first p-side guide layer 106, which is closest to the active layer, to the third p-side guide layer 108, which is furthest from the one or more p-side guide layers from the active layer 105, and the p-side electrode 113 contains at least one of Ag, Al or Rh. Here, the thickness of the first p-sided guide layer 106, which is furthest from the active layer 105 of the one or more p-sided guide layers, means the total thickness of the layers from the first p-sided guide layer 106 to the third p-sided guide layer 108. It should be noted that if one or more layers other than the p-sided guide layers are provided between the first p-sided guide layer 106 and the third p-sided guide layer 108, the total thickness means the total thickness that includes the thicknesses of the one or more layers other than the p-sided guide layers. As described above, the electrical resistance in the p-side semiconductor layer 100p can be reduced by decreasing the thickness of the p-side semiconductor outer layer 100u. This allows the operating voltage of the semiconductor laser element 100 to be reduced. Furthermore, as described above, in semiconductor laser element 100 according to the present embodiment, light loss in the p-side electrode 113 can be reduced and the power utilization efficiency of semiconductor laser element 100 can be increased by means of a p-side electrode 113 which contains at least one of Ag, Al or Rh. In semiconductor laser element 100 according to the present embodiment, the one or more p-sided guide layers can include the first p-sided guide layer 106 as an inner guide layer provided at the position closest to the active layer 105. Accordingly, light can be guided to the inner guide layer, which has a higher average refractive index than the n-doped cladding layer 102. Since light can be guided to the inner guide layer located near the active layer 105, the peak of the luminous intensity distribution can thus be brought closer to the active layer 105. In semiconductor laser element 100 according to the present embodiment, one of the one or more p-sided guide layers can be an undoped semiconductor layer. Accordingly, the loss of free carriers due to a defect in the p-side guide layer can be reduced. Thus, light loss in semiconductor laser element 100 can be reduced. In semiconductor laser element 100 according to the present embodiment, the p-side semiconductor outer layer 100u can include a p-doped contact layer 111 in contact with the p-side electrode 113. Accordingly, the contact resistance between the p-side electrode 113 and the p-side semiconductor outer layer 100u can be reduced. This allows the operating voltage of the semiconductor laser element 100 to be lowered. In semiconductor laser element 100 according to the present embodiment, the p-side semiconductor outer layer 100u can include an electron blocking layer 109. Accordingly, the flow of electrons from electron-blocking layer 109 can be prevented. Thus, the light output of semiconductor laser element 100 can be increased by increasing the recombination probability of electrons with holes in active layer 105. In semiconductor laser element 100 according to the present embodiment, the p-side semiconductor outer layer 100u can include a p-doped cladding layer 110. Accordingly, light can be confined under the p-doped cladding layer 110. This allows, for example, a reduction in light loss in the p-doped contact layer 111 and the p-side electrode 113. In the present embodiment, even if the lower edge of the bridge 110Rb is located below the uppermost surface of the p-doped cladding layer 110, an effect increasing the effective refractive index difference ΔN is achieved because the p-side electrode 113, consisting essentially of Ag, is provided above the lower surface 110Tb. Accordingly, if the effective refractive index difference ΔN is 2 × 10⁻³ or more, and the bridge width W is 30 µm, there are stably three or more modes that can propagate, and the semiconductor laser element 100 becomes a multi-transverse-mode laser element. As a result, kinks in current-light output characteristics can be prevented. Furthermore, since Ag is provided via the lower surface 110Tb, the amount of light spontaneously emitted by active layer 105, reflected by p-side electrode 113 and directed back to and reabsorbed by active layer 105, can be increased. As a result, quantum efficiency increases, the oscillation threshold can be reduced, and differential efficiency is enhanced. [Version 2] A semiconductor laser element according to embodiment 2 is described. The semiconductor laser element according to the present embodiment differs primarily from semiconductor laser element 100 according to embodiment 1 in the configuration of one or more n-sided guide layers and one or more p-sided guide layers. The semiconductor laser element according to the present embodiment is subsequently described, with the focus on the differences compared to semiconductor laser element 100 according to embodiment 1. [2-1. Overall configuration] An overall configuration of the semiconductor laser element according to the present embodiment is described with reference to Figures 4, 5 to 6. Figure 4 is a schematic cross-sectional view illustrating an overall configuration of semiconductor laser element 200 according to the present embodiment. Figure 4 shows a cross-section perpendicular to the Y-axis direction of semiconductor laser element 200, similar to Figure 2A. Figure 5 is a schematic diagram showing a distribution of bandgap energy in active layer 205 and layers in its vicinity in semiconductor laser element 200 according to the present embodiment. Figure 6 is a diagram showing configurations of layers other than the substrate 101 that are included in the semiconductor stack body 200S according to the present embodiment. As illustrated in Fig. 4, the semiconductor laser element 200 according to the present embodiment comprises a semiconductor stack body 200S, a current-blocking layer 112, a p-side electrode 113, and an n-side electrode 114. The semiconductor stack body 200S comprises a substrate 101, an n-doped cladding layer 102, one or more n-side guide layers, an active layer 205, and a p-side semiconductor layer 200p. Semiconductor laser element 200 includes first n-sided guide layer 103 and second n-sided guide layer 204 as the one or more n-sided guide layers. The p-side semiconductor layer 200p includes one or more p-side guide layers and a p-side semiconductor outer layer 200u. Semiconductor laser element 200 includes first p-side guide layer 206 and third p-side guide layer 108 as the one or more p-side guide layers. The p-side semiconductor outer layer 200u is a semiconductor layer provided above and in contact with one or more p-side guide layers. In the present embodiment, the p-side semiconductor outer layer 200u comprises an electron-blocking layer 109, a p-doped cladding layer 210, and a p-doped contact layer 211. The second n-sided guide layer 204 is an example of the one or more n-sided guide layers provided above the n-doped cladding layer 102. The second n-sided guide layer 204 is provided above the first n-sided guide layer 103. In the present embodiment, the second n-sided guide layer 204 is an undoped InXnGa1-XnN layer with a thickness of 160 nm. The bandgap energy of the second n-sided guide layer 204 increases monotonically with increasing distance from the active layer 205, and the refractive index of the second n-sided guide layer 204 increases monotonically with decreasing distance from the active layer 205. Here, the configuration in which the bandgap energy or refractive index increases monotonically includes a configuration in which a region exists where the bandgap energy or refractive index is constant in the stacking direction. In particular, the second n-sided guide layer 204 has a composition specified by InXn1Ga1-Xn1N at and near the interface on the side close to the active layer 205, and has a composition specified by InXn2Ga1-Xn2N at and near the interface on the side farthest from the active layer 205.In the present embodiment, the in-composition ratio Xn1 of the second n-sided guide layer 204 at and near the interface on the side close to the active layer 205 is 0.04, and the in-composition ratio Xn2 of this at and near the interface on the side far from the active layer 205 is 0. The in-composition ratio Xn of the second n-sided guide layer 204 decreases at a constant rate of change with increasing distance from the active layer 205. Active layer 205 is a light-emitting layer provided above one or more n-sided guide layers. In the present embodiment, active layer 205 is provided above a second n-sided guide layer 204. Active layer 205 includes pot layers 205b and 205d and barrier layers 205a, 205c, and 205e, as illustrated in Fig. 5. Barrier layer 205a is provided above a second n-sided guide layer 204 and serves as a barrier to the quantum well structure. In the present embodiment, barrier layer 205a is an undoped In0.05Ga0.95N layer with a thickness of 7 nm. Pot layer 205b is provided above barrier layer 205a and serves as a pot of the quantum well structure. Pot layer 205b is provided between barrier layer 205a and barrier layer 205c. In the present embodiment, pot layer 205b is an undoped In0.18Ga0.82N layer with a thickness of 3 nm. Barrier layer 205c is provided via pot layer 205b and serves as a barrier to the quantum well structure. In the present embodiment, barrier layer 205c is an undoped In0.05Ga0.95N layer with a thickness of 7 nm. Pot layer 205d is provided above barrier layer 205c and serves as a pot of the quantum well structure. Pot layer 205d is provided between barrier layer 205c and barrier layer 205e. In the present embodiment, pot layer 205d is an undoped In0.18Ga0.82N layer with a thickness of 3 nm. Barrier layer 205e is provided via pot layer 205d and serves as a barrier to the quantum well structure. In the present embodiment, barrier layer 205e is an undoped In0.05Ga0.95N layer with a thickness of 7 nm. The first p-sided guide layer 206 is an example of one or more p-sided guide layers provided above active layer 205. Furthermore, the first p-sided guide layer 206 is an example of an inner guide layer provided at the position nearest to the one or more p-sided guide layers of active layer 205. In the present embodiment, the first p-sided guide layer 206 is an undoped InXpGa1-XpN layer with a thickness of 280 nm. The bandgap energy of the first p-side guide layer 206 increases monotonically with increasing distance from the active layer 205, and the refractive index of the first p-side guide layer 206 increases monotonically with decreasing distance from the active layer 205. In particular, the first p-side guide layer 206 has a composition specified by InXp1Ga1-Xp1N at and near the interface on the side close to the active layer 205, and has a composition specified by InXp2Ga1-Xp2N at and near the interface on the side far from the active layer 205. In the present embodiment, the in-composition ratio Xp1 of the first p-sided guide layer 206 at and near the interface on the side close to the active layer 205 is 0.02 and its in-composition ratio Xp2 at and near the interface on the side far from the active layer 205 is 0.The in-composition ratio Xp of the first p-side guide layer 206 decreases with increasing distance from the active layer 205 at a constant rate of change. The p-doped cladding layer 210 is provided above the active layer 205. In the present embodiment, the p-doped cladding layer 210 is a p-doped Al0.035Ga0.965N layer with a thickness of 50 nm and doped with Mg at an average concentration of 2×1018 cm⁻³. The p-doped contact layer 211 is provided over the p-doped cladding layer 210 and is in ohmic contact with the p-side electrode 113. In the present embodiment, the p-doped contact layer 211 is a p-doped GaN layer with a thickness of 60 nm. The p-doped contact layer 211 is doped with Mg at an average concentration of 1 × 10²⁰ cm⁻³ as an impurity. Bridge 210R is provided in p-doped cladding layer 210 and p-doped contact layer 211 in semiconductor stack body 200S. Bridge 210R is a part that projects upwards from the lower surface 210Tb and extends in the Y-axis direction. Bridge 210R includes upper surface 210Rt and side surfaces 210Rs. Side surface 210Rs is a surface that connects the upper surface 210Rt and the lower surface 210Tb from the surfaces of bridge 210R. Side surface 210Rs is in contact with the lower surface 210Tb at the bottom edge of the bridge 210Rb. In the present embodiment, the web width W is approximately 30 µm. The lower surface 210Tb and the lower edge of the web 210Rb are located between the uppermost surface and the lowermost surface of the p-doped cladding layer 210. In the present embodiment, the lower surface 210Tb and the lower edge of the web 210Rb are located 25 nm below the uppermost surface of the p-doped cladding layer 210. Two projecting parts 210P are provided in semiconductor stack bodies 200S. These two projecting parts 210P extend upwards from the lower surface 210Tb in the Y-axis direction. A web 210R is provided between the two projecting parts 210P. Each of the two projecting parts 210P includes an upper surface 210Pt and a side surface 210Ps. A groove 210T is provided between each of the two projecting parts 210P and the web 210R. Grooves 210T are provided along the web 210R and extend in the Y-axis direction. A side surface 210Ps is a surface connecting the upper surface 210Pt and the lower surface 210Tb of the projecting part 210P. In the present embodiment, the position in the stacking direction of upper surface 210Pt of each projecting part 210P is the same as the position in the stacking direction of upper surface 210Rt of web 210R. [2-2. Effects] Effects of semiconductor laser element 200 according to the present embodiment are described. In semiconductor laser element 200 according to the present embodiment, effects similar to those achieved by semiconductor laser element 100 according to embodiment 1 are achieved. Furthermore, in semiconductor laser element 200 according to the present embodiment, the refractive index of the first p-side guide layer 206 increases with decreasing distance from the active layer 205. Accordingly, the peak of the light intensity distribution in the stacking direction can be brought close to the active layer 205. Accordingly, the light confinement coefficient can be increased in semiconductor laser element 200 according to the present embodiment. The band gap energy of the first p-side guide layer 206 can increase continuously and monotonically with increasing distance from the active layer 205. Accordingly, the valence band potential decreases continuously with increasing distance from the active layer 205. Therefore, the difference between the hole Fermi level and the valence band potential in the first p-side guide layer 206 can be kept essentially constant. In this way, the concentrations of holes and electrons in the first p-side guide layer 206 can be reduced and remain essentially constant in the stacking direction. If the magnitude of the increase (ΔEgp) in the band gap energy of the first p-side guide layer 206 in the stacking direction is small, its effects are minimal, and thus ΔEgp can be at least 100 meV. Conversely, if ΔEgp is excessively increased, the band gap energy of the first p-side guide layer 206 at the edge on the side near the active layer 205 can be small.In this case, the valence band potential of the first p-sided guide layer 206 exhibits an excessively large gradient, and thus holes injected into the active layer 205 flow to the second n-sided guide layer 204, generating a loss current. Accordingly, ΔEgp can be less than or equal to 400 meV. In this way, the free carrier concentration of the first p-side guide layer 206 in the stacking direction can be reduced, thus reducing the loss of free carriers and lowering the probability of non-radiative recombination in the semiconductor laser element 200 according to the present embodiment. Furthermore, in semiconductor laser element 200 according to the present embodiment, the in-composition ratio in the second n-sided guide layer 204 can decrease continuously and monotonically with increasing distance from the active layer 205. In this case, the refractive index of the second n-sided guide layer 204 increases continuously and monotonically with decreasing distance from the active layer 205. Accordingly, compared to the case where the refractive index in the second n-sided guide layer 204 is uniform, the region with a high refractive index of the second n-sided guide layer 204 can be brought closer to the active layer 205, thus increasing the light confinement coefficient and lowering the operating voltage. If the average in-composition ratio is less than 2%, waveguide loss can be reduced even further, and the light confinement coefficient can be increased even further. Furthermore, in the semiconductor laser element 200 according to the present embodiment, the polarization charge density of the second n-sided guide layer 204 decreases monotonically as it approaches the interface far from the active layer 205 from the interface near the active layer 205. Accordingly, the difference between a piezoelectric polarization charge density at an interface between the second n-sided guide layer 204 and the first n-sided guide layer 103 and a piezoelectric polarization charge density at an interface between the second n-sided guide layer 204 and the active layer 205 is reduced. Consequently, piezoelectric polarization charge is scattered in the stacking direction in the second n-sided guide layer 204.Accordingly, electric fields can be reduced by piezoelectric polarization at an interface between the second n-sided guide layer 204 and the first n-sided guide layer 103, and at an interface between the second n-sided guide layer 204 and the active layer 205. As a result, an increase in the conduction band potential at and near the interface between the second n-sided guide layer 204 and the first n-sided guide layer 103, and at the interface between the second n-sided guide layer 204 and the active layer 205, due to hole attraction, can be prevented. Therefore, in the semiconductor laser element 200 according to the present embodiment, the conductivity of electrons flowing from the first n-sided guide layer 103 to the active layer 205 can be increased, and thus an operating voltage can be reduced. [Variation] The configuration of the semiconductor laser element according to the present embodiment is not limited to the configuration described above. For example, active layer 205 according to the present embodiment can have a single quantum well structure comprising a single well layer. A semiconductor laser element according to a variation comprising active layer 205 with a single quantum well structure is subsequently described. Active layer 205 according to this variation includes barrier layer 205a, pot layer 205b and barrier layer 205e. Barrier layer 205a, according to this variation, is provided above the second n-sided guide layer 204 and serves as a barrier to the quantum well structure. The thickness of barrier layer 205a, located on the n-side relative to (i.e., below) well layer 205b, can be greater than the thickness of barrier layer 205e, located on the p-side relative to (i.e., above) well layer 205b. In this variation, barrier layer 205a is an undoped GaN layer with a thickness of 2.9 nm. Pot layer 205b is provided above barrier layer 205a and serves as one pot of the unique quantum well structure. Pot layer 205b is provided between barrier layers 205a and 205e. In this variation, pot layer 205b is an undoped In0.18Ga0.82N layer with a thickness of 3.4 nm. Barrier layer 205e is provided above pot layer 205b and serves as a barrier to the quantum well structure. The thickness of barrier layer 205e, located on the p-side relative to (i.e., above) pot layer 205b, can be smaller than the thickness of barrier layer 205a, located on the n-side relative to (i.e., below) pot layer 205b. In this variation, barrier layer 205e is an undoped GaN layer with a thickness of 2.0 nm. The semiconductor laser element according to this variation, which includes active layer 205 with such a configuration as above, also achieves similar effects to those achieved by semiconductor laser element 200 according to the present embodiment. It should be noted that active layer 205 may further include an intermediate barrier layer provided between n-sided barrier layer 205a and pot layer 205b. The bandgap energy of the intermediate barrier layer is greater than the bandgap energy of pot layer 205b and less than the bandgap energy of barrier layer 205a. The intermediate barrier layer consists, for example, essentially of InGaN. In this case, the in-composition ratio of the intermediate barrier layer is higher than the in-composition ratio of barrier layer 205a (0 in this variation) and less than the in-composition ratio of pot layer 205b (0.18 in this variation). The thickness of the intermediate barrier layer may, for example, be less than or equal to the thickness of barrier layer 205a. With such an intermediate barrier layer, the confinement coefficient of light in the pot layer can be increased, and the oscillation threshold can be further reduced. The bandgap energy of the intermediate barrier layer can decrease with decreasing distance from pot layer 205b. Accordingly, piezoelectric polarization charges generated at the interface between the intermediate barrier layer and pot layer 205b, and at the interface between the intermediate barrier layer and barrier layer 205a, are scattered into the intermediate barrier layer with a bandgap energy that decreases with decreasing distance from pot layer 205b. As a result, it is possible to reduce the spike-like potential barrier in the conduction band formed between barrier layer 205a and pot layer 205b when no intermediate barrier layer is present.Accordingly, the operating voltage of the semiconductor laser element can be reduced by improving the electrical conductivity of electrons flowing from the n-doped layer to pot layer 205b. To decrease the bandgap energy of the depletion layer with decreasing distance from pot layer 205b, the in-composition ratio can be increased with decreasing distance from pot layer 205b if the depletion layer is an InGaN layer. In both a structure where the bandgap energy of the depletion layer is constant and a structure where the bandgap energy decreases with decreasing distance from pot layer 205b, the average bandgap energy of the depletion layer can be greater than the average bandgap energy of pot layer 205b and less than the average bandgap energy of depletion layer 205a.Alternatively, the average in-composition ratio of the intermediate barrier layer can be lower than the average in-composition ratio of pot layer 205b and higher than the average in-composition ratio of barrier layer 205a. [Version 3] A semiconductor laser element according to embodiment 3 is described. The semiconductor laser element according to this variation differs from semiconductor laser element 200 according to embodiment 2 primarily in that it does not include an electron blocking layer and a p-doped cladding layer. The semiconductor laser element according to the present embodiment is subsequently described, with the focus on the differences compared to semiconductor laser element 200 according to embodiment 2. [3-1. Overall configuration] A complete configuration of the semiconductor laser element according to the present embodiment is described with reference to Fig. 7. Fig. 7 is a schematic cross-sectional view illustrating a complete configuration of semiconductor laser element 300 according to the present embodiment. Fig. 7 shows a cross-section perpendicular to the Y-axis direction of semiconductor laser element 300, similar to Fig. 2A. As illustrated in Fig. 7, the semiconductor laser element 300 according to the present embodiment comprises a semiconductor stack body 300S, a current-blocking layer 112, a p-side electrode 113, and an n-side electrode 114. The semiconductor stack body 300S comprises a substrate 101, an n-doped cladding layer 102, one or more n-side guide layers, an active layer 205, and a p-side semiconductor layer 300p. Semiconductor laser element 300 includes first n-sided guide layer 103 and second n-sided guide layer 204 as the one or more n-sided guide layers. The p-side semiconductor layer 300p includes one or more p-side guide layers. Semiconductor laser element 300 comprises a first p-side guide layer 306, a third p-side guide layer 308, and a p-doped contact layer 311 as the one or more p-side guide layers. In the present embodiment, since the p-side semiconductor layer 300 does not include a p-doped cladding layer, the p-doped contact layer 311 also serves as a p-side guide layer. The p-doped contact layer 311 is an example of an outer guide layer provided by the one or more p-side guide layers at the position closest to the p-side electrode 113. The first p-sided guide layer 306 is an example of one or more p-sided guide layers provided above active layer 205. Furthermore, the first p-sided guide layer 306 is an example of an inner guide layer of the one or more p-sided guide layers provided at the position closest to active layer 205. In the present embodiment, the first p-sided guide layer 306 is an undoped InXpGa1-XpN layer with a thickness of 200 nm. The third p-sided guide layer 308 is an example of the one or more p-sided guide layers provided above the active layer 205. In the present embodiment, the third p-sided guide layer 308 is an undoped GaN layer with a thickness of 20 nm. P-doped contact layer 311 is an example of the one or more p-side guide layers provided above active layer 205. P-doped contact layer 311 is a layer in ohmic contact with p-side electrode 113. In the present embodiment, p-doped contact layer 311 is a p-doped GaN layer with a thickness of 30 nm. P-doped contact layer 311 is doped with Mg at an average concentration of 1 × 10²⁰ cm⁻³ as an impurity. The web 308R is provided in the first p-side guide layer 306, the third p-side guide layer 308, and the p-doped contact layer 311 of the semiconductor stack body 300S. Web 308R is a portion that projects upward from the lower surface 308Tb and extends in the Y-axis direction. Web 308R includes the upper surface 308Rt and the side surfaces 308Rs. The side surface 308Rs connects the upper surface 308Rt and the lower surface 308Tb of web 308R. The side surface 308Rs is in contact with the lower surface 308Tb at the bottom edge of the web 308Rb. In the present embodiment, two projecting parts 308P are provided in semiconductor stack bodies 300S. The two projecting parts 308P extend upwards from the lower surface 308Tb in the Y-axis direction. A web 308R is provided between the two projecting parts 308P. Each of the two projecting parts 308P comprises an upper surface 308Pt and a side surface 308Ps. A groove 308T is provided between each of the two projecting parts 308P and the web 308R. Grooves 308T are provided along the web 308R and extend in the Y-axis direction. A side surface 308Ps is a surface connecting the upper surface 308Pt and the lower surface 308Tb of the projecting part 308P. In the present embodiment, the position in the stacking direction of upper surface 308Pt of each projecting part 308P is the same as the position in the stacking direction of upper surface 308Rt of web 308R. In the present embodiment, the bridge width W is approximately 30 µm. Furthermore, the lower surface 308Tb and the lower edge of the bridge 308Rb are located in the stacking direction between the uppermost surface of the top layer and the lowermost surface of the bottom layer of the one or more p-sided guide layers included in the semiconductor laser element 300. In other words, the lower surface 308Tb and the lower edge of the bridge 308Rb are located in the stacking direction between the uppermost surface of the p-doped contact layer 311, which is the top layer, and the lowermost surface of the first p-sided guide layer 306, which is the bottom layer, of all the p-sided guide layers included in the semiconductor laser element 300.In particular, the lower surface 308Tb and the lower edge of the web 308Rb are located in the stacking direction between the uppermost surface and the lowermost surface of the first p-sided guide layer 306, which is the lowest layer of one or more p-sided guide layers. In the present embodiment, the lower surface 308Tb and the lower edge of the web 308Rb are located 100 nm below the uppermost surface of the first p-sided guide layer 306. [3-2. Effects] In semiconductor laser element 300 according to the present embodiment, the equivalent effects of a reduction in operating voltage and reduction of light loss are achieved to those achieved by semiconductor laser element 200 according to embodiment 2. The semiconductor laser element 300 according to the present embodiment comprises: an n-doped cladding layer 102; one or more n-sided guide layers provided above the n-doped cladding layer 102; an active layer 205 provided above the one or more n-sided guide layers; one or more p-sided guide layers provided above the active layer 205; and a p-sided electrode 113 provided above the one or more p-sided guide layers and in ohmic contact with the one or more p-sided guide layers. The p-sided electrode 113 contains at least one of Ag, Al, or Rh. Accordingly, in semiconductor laser element 300, since no layer such as a p-doped cladding layer is provided between a p-side guide layer and the p-side electrode 113, and the distance between the p-side electrode 113 and the active layer 205 decreases, the electrical resistance in the p-side semiconductor layer 300p can be further reduced. Thus, the operating voltage of semiconductor laser element 300 can be lowered even further. The extent of light scattering into the p-doped contact layer 311 also increases if a p-doped cladding layer is removed, and thus the waveguide loss in the p-doped contact layer 311 increases. However, since the p-side electrode 113, which consists mainly of Ag and has a low refractive index, is provided via bridge 308R, the extent of light scattering into the p-doped contact layer 311 is reduced, and an increase in waveguide loss in the p-doped GaN contact layer can be prevented. Current-blocking layer 112 is an insulating layer provided over p-side semiconductor layer 300p. In the present embodiment, current-blocking layer 112 is transparent to light from active layer 205. As illustrated in Fig. 7, current-blocking layer 112 is provided in regions of the upper surface of p-side semiconductor layer 300p that are not the upper surface 308Rt of bridge 308R. Specifically, current-blocking layer 112 is continuously provided over lateral surfaces 308Rs of bridge 308R, lower surface 308Tb, lateral surfaces 308Ps of projecting parts 308P, each located on the side closer to bridge 308R, and upper surfaces 308Pt of projecting parts 308P. In the present embodiment, current-blocking layer 112 is a SiO2 layer. The p-side electrode 113 is a conductive layer provided above the p-side semiconductor layer 300p and in ohmic contact with the p-side semiconductor layer 300p. In the present embodiment, the p-side electrode 113 is in ohmic contact with the p-doped contact layer 311. As illustrated in Fig. 7, the p-side electrode 113 is provided above the upper surface 308Rt of the bridge 308R of the p-doped contact layer 311 and also above the side surfaces 308Rs of the bridge 308R, the lower surface 308Tb, the side surfaces 308Ps of projecting parts 308P (each on the side closer to the bridge 308R), and the upper surfaces 308Pt of projecting parts 308P via the current-blocking layer 112. In the present embodiment, the lower edge of the web 308Rb is located in the stacking direction between the top surface of the top layer and the bottom surface of the bottom layer of the one or more p-sided guide layers included in the semiconductor laser element 300. This reduces the distance between the lower edge of the web 308Rb and the active layer 205. Consequently, the effective refractive index difference ΔN is increased. In the present embodiment, the lower edge of the web 308Rb is located in the stacking direction between the top surface and the bottom surface of the first p-sided guide layer 306, which is the bottom layer of the one or more p-sided guide layers included in the semiconductor laser element 300, and thus, in particular, the distance between the lower edge of the web 308Rb and the active layer 205 is reduced.As a result, an increase in effective refractive index difference ΔN becomes even more noticeable. Thus, even if the effective refractive index difference ΔN changes due to variations in the thickness and composition of the element structure during the element manufacturing process, it is possible to achieve a stable effective refractive index difference ΔN with a value of at least 2 × 10⁻³. Accordingly, if the effective refractive index difference ΔN is 2 × 10⁻³ or higher, there are stably three or more modes that can propagate, since the bridge width W is 30 µm, and the semiconductor laser element 300 becomes a multi-transverse-mode laser element. As a result, current-light output characteristics with prevented kinking can be obtained with favorable reproducibility. Furthermore, since the lower edge of the web 308Rb is located in the stacking direction between the top surface and the bottom surface of a p-sided guide layer included in one or more p-sided guide layers, and the p-sided electrode 113, which consists essentially of Ag, is provided above the lower surface 308Tb, the distance between the p-sided electrode 113 above the lower surface 308Tb and the active layer 205 is reduced. In the present embodiment, the lower edge of the web 308Rb is located in the stacking direction between the top surface and the bottom surface of the first p-sided guide layer 306, which is the bottom layer of one or more p-sided guide layers, and thus, in particular, the distance between the p-sided electrode 113 and the active layer 205 is reduced.Accordingly, the amount of light spontaneously emitted by active layer 205, reflected by p-side electrode 113, and redirected back to and reabsorbed by active layer 205 can be increased. As a result, quantum efficiency increases, the oscillation threshold can be reduced, and differential efficiency is enhanced. Additionally, since the p-side semiconductor layer 300p lacks a p-doped cladding layer and each guide layer is undoped, the attenuation of spontaneously emitted light lost due to absorption by free carriers can be prevented. This increases the amount of spontaneously emitted light that is redirected, further enhancing the quantum efficiency in active layer 205 and further reducing the oscillation threshold. Consequently, the differential efficiency also increases. [Version 4] A semiconductor laser element according to embodiment 4 is described. The semiconductor laser element according to the present embodiment differs primarily from semiconductor laser element 100 according to embodiment 1 in that an electron blocking layer is provided, for example, between the first p-sided guide layer and the second p-sided guide layer. The semiconductor laser element according to the present embodiment is subsequently described, with the focus on the differences compared to semiconductor laser element 100 according to embodiment 1. [4-1. Overall configuration] An overall configuration of the semiconductor laser element according to the present embodiment is described with reference to Figures 8, 9 to 10. Figure 8 is a schematic cross-sectional view illustrating an overall configuration of semiconductor laser element 400 according to the present embodiment. Figure 8 shows a cross-section perpendicular to the Y-axis direction of semiconductor laser element 400, similar to Figure 2A. Figure 9 is a schematic diagram showing a distribution of bandgap energy and a distribution of defect concentration of semiconductor laser element 400 according to the present embodiment in the stacking direction. Figure 10 is a diagram showing configurations of layers other than the substrate 101 that are included in semiconductor stack bodies 400S according to the present embodiment. As illustrated in Fig. 8, the semiconductor laser element 400 according to the present embodiment comprises a semiconductor stack body 400S, a current-blocking layer 112, a p-side electrode 113, an adhesion layer 421, a pad electrode 422, and an n-side electrode 114. The semiconductor stack body 400S comprises a substrate 101, a base layer 431, a buffer layer 432, an n-doped cladding layer 402, one or more n-side guide layers, an active layer 405, and a p-side semiconductor layer 400p. An element isolation groove 10T is provided in each lateral surface (end face in the X-axis direction) of the semiconductor stack body 400S. The element isolation groove 10T is a groove for singulating semiconductor laser elements 400. Semiconductor laser element 400 includes first n-sided guide layer 403 and second n-sided guide layer 404 as the one or more n-sided guide layers. The p-side semiconductor layer 400p includes one or more p-side guide layers, first intermediate layer 441, electron blocking layer 409, second intermediate layer 442 and p-side semiconductor outer layer 400u. Semiconductor laser element 400 includes first p-side guide layer 406 and second p-side guide layer 407 as the one or more p-side guide layers. The p-side semiconductor outer layer 400u is a semiconductor layer provided above and in contact with one or more p-side guide layers. In the present embodiment, the p-side semiconductor outer layer 400u comprises a p-doped cladding layer 410 and a p-doped contact layer 411. Base layer 431 is an n-doped semiconductor layer provided via substrate 101. Base layer 431 can have an average Al composition ratio that is lower than that of n-doped cladding layer 402. In the present embodiment, base layer 431 is an n-doped Al0.02Ga0.98N layer with a thickness of 1000 nm, doped with Si at an average concentration of 1.0 × 10¹⁸ cm⁻³ and provided via substrate 101, as illustrated in Fig. 10. Buffer layer 432 is an n-doped semiconductor layer provided between substrate 101 and n-doped cladding layer 402. In the present embodiment, buffer layer 432 is provided above base layer 431. In the present embodiment, buffer layer 432 comprises an n-doped GaN layer with a thickness of 10 nm and doped with Si at an average concentration of 1.0×1018cm-3, an n-doped In0.04Ga0.96N layer with a thickness of 150 nm, doped with Si at an average concentration of 1.0×1018cm-3 and provided above the n-doped GaN layer, and an n-doped GaN layer with a thickness of 10 nm, doped with Si at an average concentration of 1.0×1018cm-3 and provided above the n-doped In0.04Ga0.96N layer. N-doped cladding layer 402 is an n-doped nitride-based semiconductor layer containing Al and provided via substrate 101. In the present embodiment, n-doped cladding layer 402 is provided via buffer layer 432. The average Al composition ratio of n-doped cladding layer 402 is higher than the average Al composition ratio of one or more n-sided guide layers. The average Al composition ratio of n-doped cladding layer 402 can be lower than 10%. In the present embodiment, n-doped cladding layer 402 is an n-doped Al0.065Ga0.935N layer with a thickness of 1500 nm and doped with Si at an average concentration of 1 × 10¹⁸ cm⁻³. In the present disclosure, the average Al composition ratio of a layer refers to the value of an Al composition ratio obtained by integrating the orders of magnitude of the Al composition ratios at positions in the stacking direction of the layer from the position of the interface on the side near substrate 101 to the position of the interface on the side far from substrate 101 in the stacking direction of the layer and dividing the resulting value by the thickness of the layer. The first n-sided guide layer 403 is a nitride-based semiconductor layer containing Al and provided over an n-doped cladding layer 402. The first n-sided guide layer 403 has a higher average refractive index and a lower average bandgap energy than the n-doped cladding layer 402. The average Al composition ratio of the first n-sided guide layer 403 can be less than 10%. In the present embodiment, the first n-sided guide layer 403 is an n-doped Al0.04Ga0.96N layer with a thickness of 127 nm and doped with Si at an average concentration of 1 × 10¹⁸ cm⁻³. The second n-sided guide layer 404 is a nitride-based semiconductor layer containing Al and is provided over the n-doped cladding layer 402. In the present embodiment, the second n-sided guide layer 404 is provided over the first n-sided guide layer 403. The second n-sided guide layer 404 has a higher average refractive index and a lower average bandgap energy than the n-doped cladding layer 402. The average Al composition ratio of the second n-sided guide layer 404 can be less than 10%. In the present embodiment, the second n-sided guide layer 404 is an undoped Al0.03Ga0.97N layer with a thickness of 80 nm. Active layer 405 is a light-emitting layer provided above one or more n-sided guide layers. In the present embodiment, active layer 405 is provided above a second n-sided guide layer 404. Active layer 405 is a nitride-based semiconductor layer comprising pot layer 405b and Al-containing barrier layers 405a and 405c, as illustrated in Fig. 9. Pot layer 405b is provided between barrier layer 405a and barrier layer 405c. In the present embodiment, active layer 405 emits ultraviolet light of about 375 nm. It should be noted that the configuration of active layer 405 is not limited thereto. For example, active layer 405 can have a multi-quantum pot structure. In particular, active layer 405 can include three or more barrier layers and two or more pot layers.Thus, active layer 405 includes one or more pot layers and a variety of barrier layers. Barrier layers 405a and 405c are nitride-based semiconductor layers provided above one or more n-sided guide layers and serve as barriers of the quantum well structure. Barrier layer 405c is provided above barrier layer 405a. In the present embodiment, the average bandgap energy of each of barrier layers 405a and 405c is greater than the average bandgap energy of well layer 405b. In the present embodiment, barrier layer 405a is an undoped Al0.04Ga0.96N layer with a thickness of 7 nm. Barrier layer 405c is an undoped Al0.05Ga0.95N layer with a thickness of 5 nm. Pot layer 405b is a nitride-based semiconductor layer provided via barrier layer 405a and serves as a pot of the quantum well structure. In the present embodiment, pot layer 405b is an undoped In0.01Ga0.99N layer with a thickness of 17.5 nm. The first p-sided guide layer 406 is a nitride-based semiconductor layer containing Al, located between the active layer 405 and the electron-blocking layer 409. In the present embodiment, the first p-sided guide layer 406 is located beneath the first intermediate layer 441. The first p-sided guide layer 406 has a higher average refractive index and a lower average bandgap energy than at least one of the n-doped cladding layers 402 or p-doped cladding layers 410. Furthermore, the average bandgap energy of the first p-sided guide layer 406 is lower than the average bandgap energy of the second intermediate layer 442 and the average bandgap energy of the barrier layer 405c, which is the highest of the plurality of barrier layers in the active layer 405 (i.e., closest to the electron-blocking layer 409).Accordingly, electrical conduction of holes (positive holes) from the p-doped cladding layer 410 to the active layer 405 is easier. Therefore, the operating voltage of the semiconductor laser element 400 can be reduced. In the present embodiment, the average band gap energy of the first p-side guide layer 406 is lower than the average band gap energy of the first intermediate layer 441. An AlGaInN layer can be used as the first p-side guide layer 406. The thickness of the first p-side guide layer 406 is, for example, at least 9 nm and at most 60 nm. In the present embodiment, the first p-side guide layer 406 is an undoped Al0.04Ga0.947In0.013N layer with a thickness of 9 nm. The first intermediate layer 441 is a nitride-based semiconductor layer provided between the first p-side guide layer 406 and the electron-blocking layer 409 and contains Al. The average bandgap energy of the first intermediate layer 441 is greater than the average bandgap energy of the first p-side guide layer 406 and less than the average bandgap energy of the electron-blocking layer 409. In the present embodiment, the first intermediate layer 441 is a p-doped Al0.04Ga0.96N layer with a thickness of 3 nm. The first intermediate layer 441 can be doped with a p-doped impurity at an average concentration of at most 2.0 × 10¹⁸ cm⁻³ (the first intermediate layer 441 can be undoped). Electron blocking layer 409 is a p-doped nitride-based semiconductor layer provided above active layer 405 and containing Al. The average bandgap energy of electron blocking layer 409 is greater than the average bandgap energy of barrier layer 405c. Accordingly, electron leakage from active layer 405 to p-doped cladding layer 410 can be prevented. In the present embodiment, the average bandgap energy of electron blocking layer 409 is greater than the average bandgap energy of each of first intermediate layer 441, second intermediate layer 442, and p-doped cladding layer 410. The average impurity concentration of electron blocking layer 409 is higher than the average impurity concentration of each of first intermediate layer 441, second intermediate layer 442, first p-side guide layer 406, and second p-side guide layer 407.In the present embodiment, electron blocking layer 409 is a p-doped Al0,36Ga0,64N layer with a thickness of 1.6 nm and doped with Mg at an average concentration of 1.5×1019cm-3. The second intermediate layer 442 is a p-doped nitride-based semiconductor layer provided via electron-blocking layer 409 and containing Al. In the present embodiment, the second intermediate layer 442 is a p-doped Al0.05Ga0.95N layer with a thickness of 56 nm and doped with Mg at an average concentration of 1.0 × 10¹⁹ cm⁻³. The second p-sided guide layer 407 is a nitride-based semiconductor layer provided via electron-blocking layer 409 and contains Al. In the present embodiment, the second p-sided guide layer 407 is provided via the second intermediate layer 442. In the present embodiment, the average band gap energy of the second p-sided guide layer 407 is lower than the average band gap energy of the second intermediate layer 442 and the p-doped cladding layer 410. The average Al composition ratio of the second p-sided guide layer 407 can be lower than 10%. In the present embodiment, the second p-sided guide layer 407 is a p-doped Al0.03Ga0.97N layer with a thickness of 50 nm and doped with Mg at an average concentration of 2.0 × 10¹⁸ cm⁻³. The p-doped cladding layer 410 is a p-doped nitride-based semiconductor layer containing Al and provided above a second p-side guide layer 407. The average bandgap energy of the p-doped cladding layer 410 is lower than the average bandgap energy of the electron-blocking layer 409. The average Al composition ratio of the p-doped cladding layer 410 can be less than 10%. The impurity concentration at a boundary region of the p-doped cladding layer 410 on the side near the active layer 405 can be lower than the impurity concentration at a boundary region of the p-doped cladding layer 410 on the side farther from the active layer 405. Accordingly, the impurity concentration in a region of the p-doped cladding layer 410 where the light intensity is high can be reduced, and thus the loss of free light carriers due to an impurity can be reduced.In the present embodiment, p-doped shell layer 410 is a p-doped Al0,065Ga0,935N layer with a thickness of 30 nm and doped with Mg at an average concentration of 2.0×1018cm-3. The p-doped contact layer 411 is a p-doped nitride-based semiconductor layer provided above the p-doped cladding layer 410 and in ohmic contact with the p-side electrode 113. In the present embodiment, the p-doped contact layer 411 comprises a p-doped GaN layer with a thickness of 30 nm and doped with Mg at an average concentration of 2.0 × 10¹⁹ cm⁻³, and a p-doped GaN layer with a thickness of 10 nm, doped with Mg at an average concentration of 2.0 × 10²⁰ cm⁻³, provided above the aforementioned p-doped GaN layer. Bridge 410R is provided in the second intermediate layer 442, the second p-side guide layer 407, the p-doped cladding layer 410, and the p-doped contact layer 411 of the semiconductor stack body 400S. Bridge 410R is a portion that projects upward from the lower surface 410Tb and extends in the Y-axis direction. Bridge 410R includes the upper surface 410Rt and the side surfaces 410Rs. The side surface 410Rs is a surface that connects the upper surface 410Rt and the lower surface 410Tb of bridge 410R. The side surface 410Rs is in contact with the lower surface 410Tb at the bridge's lower edge 410Rb. In the present embodiment, two projecting parts 410P are provided in semiconductor stack bodies 400S. The two projecting parts 410P are parts that project upwards from the lower surface 410Tb and extend in the Y-axis direction. A web 410R is provided between the two projecting parts 410P. Each of the two projecting parts 410P includes an upper surface 410Pt and a side surface 410Ps. A groove 410T is provided between each of the two projecting parts 410P and the web 410R. Grooves 410T are provided along the web 410R and extend in the Y-axis direction. The side surface 410Ps is a surface that connects the upper surface 410Pt and the lower surface 410Tb of the surfaces of the projecting part 410P. In the present embodiment, the position in the stacking direction of upper surface 410Pt of each projecting part 410P is the same as the position in the stacking direction of upper surface 410Rt of web 410R. In the present embodiment, the web width W is approximately 15 µm. Furthermore, the lower surface 410Tb and the lower edge of the web 410Rb are located in the stacking direction between the uppermost surface of the top layer and the lowermost surface of the bottom layer of one or more p-sided guide layers included in the semiconductor laser element 400. In particular, the lower surface 410Tb and the lower edge of the web 410Rb are located between the uppermost surface and the lowermost surface of the second intermediate layer 442 in the stacking direction. As illustrated in Fig. 8, dc denotes the distance between the lower edge of the web 410Rb and the electron blocking layer 409. In the present embodiment, the distance dc is 35 nm. Current-blocking layer 112 is an insulating layer provided over p-doped cladding layer 410. In the present embodiment, current-blocking layer 112 is an insulating layer that transmits light from active layer 405. Current-blocking layer 112 is provided in regions of the upper surface of semiconductor stack body 400S that are not the upper surface of bridge 410R. It should be noted that current-blocking layer 112 can also be provided in a subregion of the upper surface of bridge 410R. For example, current-blocking layer 112 can also be provided in marginal regions of the upper surface of bridge 410R. In the present embodiment, current-blocking layer 112 is a SiO2 layer with a thickness of 300 nm. The p-side electrode 113 is a conductive layer provided over a p-doped contact layer 411. In the present embodiment, the p-side electrode 113 is in contact with the p-doped contact layer 411. The p-side electrode 113 contains at least one of Ag, Al, or Rh. In the present embodiment, the p-side electrode 113 includes an Ag layer with a thickness of 100 nm and a Pt layer with a thickness of 100 nm, which is provided over the Ag layer. The adhesion layer 421 is a metal layer provided between the current-blocking layer 112 and the pad electrode 422. The adhesion layer 421 serves to improve the adhesion of the pad electrode 422. The adhesion layer 421 is provided over the lateral surfaces 410Rs of the bridge 410R, the lower surface 410Tb, the lateral surfaces 410Ps of the projecting parts 410P (each on the side closer to the bridge 410R), and the upper surfaces 410Pt of the projecting parts 410P, above the current-blocking layer 112. It should be noted that the adhesion layer 421 can also be provided over the p-side electrode 113. In the present embodiment, adhesion layer 421 includes a Ti layer with a thickness of 10 nm and which is provided over current-blocking layer 112, and a Pt layer with a thickness of 100 nm and which is provided over the Ti layer.It should be noted that in adhesion layer 421, a layer consisting essentially of a material that absorbs laser light, such as Cr or Ni, can be used instead of the Ti layer. Pad electrode 422 is a pad-shaped electrode provided via p-side electrode 113. In the present embodiment, pad electrode 422 is provided via p-side electrode 113 and adhesion layer 421. In the present embodiment, pad electrode 422 is an Au layer with a thickness of 2.0 µm. [4-2. Effects] The semiconductor laser element 400 according to the present embodiment comprises: an n-doped cladding layer 402; one or more n-sided guide layers provided above the n-doped cladding layer 402; an active layer 405 provided above the one or more n-sided guide layers; a p-sided semiconductor layer 400p provided above the active layer 405; and a p-sided electrode 113 provided above the p-sided semiconductor layer 400p and in ohmic contact with the p-sided semiconductor layer 400p.Active layer 405 includes one or more pot layers, a second distance between p-side electrode 113 and pot layer 405b, which is closest to the one or more pot layers of p-side electrode 113, is shorter than a first distance between n-doped sheath layer 402 and pot layer 405b, which is closest to the one or more pot layers of n-doped sheath layer 402, and p-side electrode 113 contains at least one of Ag, Al or Rh. In the present embodiment, the first distance is equal to the total thickness of the first n-sided guide layer 403, the second n-sided guide layer 404, and the barrier layer 405a. The second distance is equal to the total thickness of the barrier layer 405c, the first p-sided guide layer 406, the first intermediate layer 441, the electron barrier layer 409, the second intermediate layer 442, the second p-sided guide layer 407, the p-doped shell layer 410, and the p-doped contact layer 411. If bridge 410R is provided in the p-doped shell layer 410, the second distance represents the distance between the pot layer 405b and the p-sided electrode 113 in the region containing bridge 410R. As described above, since in semiconductor laser element 400, according to the present embodiment, the second distance is shorter than the first distance, the electrical resistance in the p-side semiconductor layer 400p can be further reduced. Thus, the operating voltage of semiconductor laser element 400 can be further lowered. In semiconductor laser element 400 according to the present embodiment, the p-sided semiconductor layer 400p can include one or more p-sided guide layers and a p-sided semiconductor outer layer 400u, which is provided above the one or more p-sided guide layers and in contact with the one or more p-sided guide layers. Accordingly, light can be confined to one or more p-sided guide layers by making the average refractive index of such a p-sided semiconductor outer layer 400u lower than that of the one or more p-sided guide layers. In semiconductor laser element 400 according to the present embodiment, the p-side semiconductor outer layer 400u can have a thickness less than the thickness from a p-side guide layer (first p-side guide layer 406) from one or more p-side guide layers that is closer to active layer 405 to a p-side guide layer (second p-side guide layer 407) that is furthest away from active layer 405. As described above, the electrical resistance in the p-side semiconductor layer 400p can be reduced by decreasing the thickness of the p-side semiconductor outer layer 400u. This allows the operating voltage of the semiconductor laser element 400 to be lowered. In semiconductor laser element 400 according to the present embodiment, the p-side semiconductor layer 400p can include one or more p-side guide layers and the p-side electrode 113 can be in ohmic contact with the one or more p-side guide layers. Accordingly, in semiconductor laser element 400, since no layer such as a p-doped cladding layer is provided between the p-side guide layer and the p-side electrode 113, the electrical resistance in the p-side semiconductor layer 400p can be further reduced. Thus, the operating voltage of semiconductor laser element 400 can be lowered even further. In semiconductor laser element 400 according to the present embodiment, similar to semiconductor laser element 100 according to embodiment 1, the thickness of the p-side semiconductor outer layer 400u beneath the one or more pot layers included in active layer 405 is less than the first distance between pot layer 405b, which is closest to the n-doped cladding layer 402, and the n-doped cladding layer 402 and the p-side electrode 113, which contains at least one of Ag, Al, or Rh. The thickness of the p-side semiconductor outer layer 400u can also be less than the thickness of the first p-side guide layer 406, which is closest to active layer 405, to the second p-side guide layer 407, which is furthest from the one or more p-side guide layers.Here, the thickness from the first p-side guide layer 406 to the second p-side guide layer 407 includes not only the thicknesses of the first p-side guide layer 406 and the second p-side guide layer 407, but also the thicknesses of one or more layers provided in between. Thus, the thickness from the first p-side guide layer 406 to the second p-side guide layer 407 represents the total thickness of the first p-side guide layer 406, the first intermediate layer 441, the electron blocking layer 409, the second intermediate layer 442, and the second p-side guide layer 407. Accordingly, in semiconductor laser element 400 according to the present embodiment, the operating voltage and light loss can be reduced, similar to semiconductor laser element 100 according to embodiment 1. In semiconductor laser element 400 according to the present embodiment, the one or more p-sided guide layers include a first p-sided guide layer 406, which is an inner guide layer provided at the position nearest to the active layer 405, and a second p-sided guide layer 407, which is an outer guide layer provided at the position nearest to the p-sided electrode 113, and semiconductor laser element 400 may include an electron blocking layer 409 provided between the outer guide layer and the inner guide layer. Accordingly, the flow of electrons from electron-blocking layer 409 can be prevented. Thus, the light output of semiconductor laser element 400 can be increased by increasing the recombination probability of electrons with holes in active layer 405. The semiconductor laser element 400 according to the present embodiment can include, via an electron-blocking layer 409, a second intermediate layer 442 with an average bandgap energy that is lower than that of the electron-blocking layer 409 and higher than that of the second p-side guide layer 407. The average impurity concentration of the second intermediate layer 442 is lower than the average impurity concentration of the electron-blocking layer 409 and higher than the average impurity concentration of the second p-side guide layer 407. As described above, the semiconductor laser element 400 according to the present embodiment includes a second intermediate layer 442 with a higher average bandgap energy than that of the second p-side guide layer 407, in a region where the impurity concentration is high, above the electron blocking layer 409. Thus, the light absorption edge in this region can be shifted to the side with higher energy (shorter wavelength). Therefore, light absorption in this region can be prevented in the semiconductor laser element 400 according to the present embodiment. As described above, light loss can be reduced in the semiconductor laser element 400 according to the present embodiment, while the aluminum composition ratios of the layers, such as the second p-side guide layer 407 and the p-doped cladding layer 410, can be lowered. The semiconductor laser element 400 according to the present embodiment can include a first p-sided guide layer 406 which is provided between the active layer 405 and the electron blocking layer 409. Accordingly, the peak of the light intensity distribution can be brought closer to the active layer 405, thus reducing the operating voltage and operating current of the semiconductor laser element 400 and increasing the light confinement coefficient and socket efficiency (WPE). In semiconductor laser element 400 according to the present embodiment, the band gap energy of the first p-side guide layer 406 can be less than or equal to the band gap energy of the adjacent barrier layer 405c. Accordingly, the refractive index of the first p-side guide layer 406 can be increased and the electrical conductivity can be increased. In semiconductor laser element 400 according to the present embodiment, the band gap energy of the first p-side guide layer 406 can be less than or equal to the band gap energy of the second p-side guide layer 407. Accordingly, the refractive index of the first p-side guide layer 406 can be greater than or equal to the refractive index of the second p-side guide layer 407, and thus the operating voltage and operating current can be reduced and the light limiting coefficient, the effective refractive index difference and WPE can be increased. In semiconductor laser element 400 according to the present embodiment, the first p-side guide layer 406 can be an undoped AlGaInN layer. Accordingly, light absorption due to an increase in impurity concentration can be prevented. Furthermore, by using an AlGaInN layer as the first p-side guide layer 406, an AlGaInN layer, which is a compressive stress layer with respect to substrate 101, can be provided under and near web 410R. Consequently, shear stress at the lower edge of web 410R can be reduced due to the presence of an AlGaInN layer, which is a tensile stress layer with respect to substrate 101. Additionally, wafer warping, which is the base material used in the fabrication of semiconductor laser element 400, can be prevented, and the occurrence of wafer breakage during the process after stacking the first p-side guide layer 406 can be avoided. In the semiconductor laser element 400 according to the present embodiment, the Al composition ratio of the first p-side guide layer 406 can be equal to the Al composition ratio of the adjacent junction layer 405c. In this case, if the junction layer 405c and the first p-side guide layer 406 are deployed sequentially, it is sufficient to change only the Al composition ratio in the deployment process of the first p-side guide layer 406 compared to that in the deployment process of the junction layer 405c. Since the controllability of the atomic composition can be improved in the deployment process of the first p-side guide layer 406, the in-plane distribution (distribution within the plane perpendicular to the stacking direction) of the composition of the first p-side guide layer 406 can thus be made uniform.As a result, if, for example, many semiconductor laser elements 400 are placed on a wafer, the properties of semiconductor laser elements 400 can become uniform. In the semiconductor laser element 400 according to the present embodiment, the in-composition ratio of the first p-side guide layer 406 can change depending on its position in the stacking direction. For example, the in-composition ratio in a region of the first p-side guide layer 406 near the active layer 405 can be higher than the in-composition ratio in a region far from the active layer 405. Accordingly, the band gap energy in a region of the first p-side guide layer 406 near the active layer 405 can be reduced, and thus the hole conductivity in this region can be increased. Therefore, the operating voltage of the semiconductor laser element 400 can be further reduced. Furthermore, if semiconductor laser element 400 is an ultraviolet laser element incorporating substrate 101, which is essentially GaN, the following problems arise. In this case, since the effective refractive index of semiconductor laser element 400 with respect to a waveguide mode is lower than the refractive index of substrate 101, light leakage (light components flowing out of substrate 101) occurs if light in the waveguide mode reaches the substrate and propagates within it without attenuating in the waveguide mode. Due to the low refractive index of slot 410T, the light distribution in an outer region of the slot (directly below slot 410T) propagates more strongly to substrate 101 in the waveguide mode than the light distribution in an inner region of the slot (the light distribution directly below slot 410R). Thus, it is highly likely that the light will become components that flow to substrate 101.If components flowing to substrate 101 are present in the light distribution in the outer region of the web, the effective refractive index of the light distribution in the stacking direction in the outer region of the web becomes higher than the effective refractive index of the light distribution in the stacking direction in the inner region of the web, leading to an index-antiguided state. When the index-antiguided state occurs, the light distribution in the inner region of the web cannot be stably confined in the horizontal direction (the X-axis direction), and thus kinks in the current-light output characteristics easily occur, resulting in a decrease in differential efficiency and an increase in the oscillation threshold. Furthermore, if the web width W is narrow, the proportion of the light distribution present in the outer region of the web increases in the waveguide mode.Accordingly, with a narrower bridge width W, light components are more likely to occur that flow into substrate 101. To prevent the generation of light components that flow into substrate 101 in the light distribution in the outer region of the bridge, the effective refractive index difference ΔN can be increased when the bridge width W is narrowed. If the bridge width W is 15 µm, the effective refractive index difference ΔN can be a high value of at least 1.0 × 10⁻². In the semiconductor laser element 400 according to the present embodiment, providing a second p-sided guide layer 407 with a high refractive index within the bridge 410R serves to spread the light distribution in the waveguide mode into the bridge interior region, thus increasing the effective refractive index of the light distribution in the stacking direction in the bridge interior region. As a result, the effective refractive index difference ΔN is increased. By increasing the effective refractive index difference ΔN, the proportion of the light distribution present in a region outside the bridge can be reduced in the light distribution in the waveguide mode. Consequently, the generation of light components that flow to substrate 101 is prevented.Furthermore, according to the present embodiment, the semiconductor laser element 400 can reduce the extent of the light distribution propagating into the p-doped contact layer 411 by incorporating a p-doped cladding layer 410, thus preventing waveguide loss in the p-doped contact layer 411. Moreover, by providing a lower surface 410Tb and a ridge bottom edge 410Rb in a p-side guide layer (above the electron barrier layer 409) and using a material that strongly absorbs light, such as titanium, for the metal provided above the lower surface 410Tb, the light distribution propagating into the ridge outer region can be attenuated by the absorption loss of the material, thus preventing the generation of light components flowing to substrate 101. In the present embodiment, the lower edge of the web 410Rb is located in the stacking direction between the top surface of the top layer and the bottom surface of the bottom layer of the one or more p-sided guide layers included in the semiconductor laser element 400. This reduces the distance between the lower edge of the web 410Rb and the active layer 405. Consequently, the effective refractive index difference ΔN is increased. Thus, even if the effective refractive index difference ΔN changes due to variations in the thickness and composition of the element structure during the element fabrication process, it is possible to obtain a stable effective refractive index difference ΔN with a value of at least 2 × 10⁻³. [Version 5] A semiconductor laser element according to embodiment 5 is described. The semiconductor laser element according to the present embodiment differs from semiconductor laser element 400 according to embodiment 4 primarily in that it does not include a p-side semiconductor outer layer. The semiconductor laser element according to the present embodiment is subsequently described, with the focus on the differences compared to semiconductor laser element 400 according to embodiment 4. [5-1. Overall configuration] A complete configuration of the semiconductor laser element according to the present embodiment is described with reference to Fig. 11. Fig. 11 is a schematic cross-sectional view illustrating a complete configuration of semiconductor laser element 500 according to the present embodiment. Fig. 11 shows a cross-section perpendicular to the Y-axis direction of semiconductor laser element 500, similar to Fig. 2A. As illustrated in Fig. 11, the semiconductor laser element 500 according to the present embodiment comprises a semiconductor stack body 500S, a current-blocking layer 112, a p-side electrode 113, an adhesion layer 421, a pad electrode 422, and an n-side electrode 114. The semiconductor stack body 500S comprises a substrate 101, a base layer 431, a buffer layer 432, an n-doped cladding layer 402, one or more n-side guide layers, an active layer 405, and a p-side semiconductor layer 500p. The p-side semiconductor layer 500p includes one or more p-side guide layers, first intermediate layer 441, electron blocking layer 409 and second intermediate layer 442. Semiconductor laser element 500 includes first p-side guide layer 406, second p-side guide layer 507 and p-doped contact layer 511 as the one or more p-side guide layers. The second p-sided guide layer 507 according to the present embodiment is a nitride-based semiconductor layer provided via electron-blocking layer 409 and containing Al. In the present embodiment, the second p-sided guide layer 507 is provided via a second intermediate layer 442. In the present embodiment, the average band gap energy of the second p-sided guide layer 507 is lower than the average band gap energy of the second intermediate layer 442. The average Al composition ratio of the second p-sided guide layer 507 can be lower than 10%. In the present embodiment, the second p-sided guide layer 507 is a p-doped Al0.03Ga0.97N layer with a thickness of 50 nm and doped with Mg at an average concentration of 2.0 × 10¹⁹ cm⁻³. The p-doped contact layer 511 is a p-doped nitride-based semiconductor layer in ohmic contact with the p-side electrode 113. In the present embodiment, the p-doped contact layer 511 also serves as a p-side guide layer. The p-doped contact layer 511 is a p-doped Al0.03Ga0.97N layer with a thickness of 10 nm and doped with Mg at an average concentration of 2.0 × 10²⁰ cm⁻³. Bridge 507R is provided in the second intermediate layer 442, the second p-side guide layer 507, and the p-doped contact layer 511 of semiconductor stack body 500S. Bridge 507R is a portion that projects upward from the lower surface 507Tb and extends in the Y-axis direction. Bridge 507R comprises the upper surface 507Rt and the side surfaces 507Rs. Side surface 507Rs is a surface that connects the upper surface 507Rt and the lower surface 507Tb of bridge 507R. Side surface 507Rs is in contact with the lower surface 507Tb at the bridge's lower edge 507Rb. In the present embodiment, two projecting parts 507P are provided in semiconductor stack bodies 500S. The two projecting parts 507P extend upwards from the lower surface 507Tb in the Y-axis direction. A web 507R is provided between the two projecting parts 507P. Each of the two projecting parts 507P comprises an upper surface 507Pt and a side surface 507Ps. A groove 507T is provided between each of the two projecting parts 507P and the web 507R. Grooves 507T are provided along the web 507R and extend in the Y-axis direction. A side surface 507Ps is a surface connecting the upper surface 507Pt and the lower surface 507Tb of the surfaces of the projecting part 507P. In the present embodiment, the position in the stacking direction of upper surface 507Pt of each projecting part 507P is the same as the position in the stacking direction of upper surface 507Rt of web 507R. In the present embodiment, the web width W is approximately 15 µm. The lower surface 507Tb and the lower edge of the web 507Rb are located between the uppermost surface and the lowermost surface of the second intermediate layer 442 in the stacking direction. [5-2. Effects] In semiconductor laser element 500 according to the present embodiment, effects similar to those achieved by semiconductor laser element 400 according to embodiment 4 are also achieved. In semiconductor laser element 500 according to the present embodiment, the p-side semiconductor layer 500p includes one or more p-side guide layers and the p-side electrode 113 is in ohmic contact with the one or more p-side guide layers. Accordingly, since no layer such as a p-doped cladding layer is provided between the p-side guide layer and the p-side electrode 113 in semiconductor laser element 500, the electrical resistance in the p-side semiconductor layer 500p can be further reduced. Thus, the operating voltage of semiconductor laser element 500 can be lowered even further. Furthermore, since no p-doped cladding layer with a low refractive index is provided in the bridge, the effective refractive index of the vertical light distribution inside the bridge increases, and ΔN is increased. When ΔN is increased, the proportion of the light distribution outside the bridge can be reduced in the waveguide mode. Consequently, the generation of light components that flow to the substrate is prevented. [Version 6] A semiconductor laser element according to embodiment 6 is described. The semiconductor laser element according to the present embodiment differs from semiconductor laser element 400 according to embodiment 4 in the configurations of the active layer and the first p-side guide layer. The semiconductor laser element according to the present embodiment is subsequently described, with the focus on the differences compared to semiconductor laser element 400 according to embodiment 4. [6-1. Overall configuration] An overall configuration of the semiconductor laser element according to the present embodiment is described with reference to Figures 12 and 13. Figure 12 is a schematic cross-sectional view illustrating an overall configuration of semiconductor laser element 600 according to the present embodiment. Figure 12 shows a cross-section perpendicular to the Y-axis direction of semiconductor laser element 600, similar to Figure 2A. Figure 13 is a schematic diagram showing a distribution of bandgap energy and a distribution of defect concentration of semiconductor laser element 600 according to the present embodiment in the stacking direction. As illustrated in Fig. 12, the semiconductor laser element 600 according to the present embodiment comprises a semiconductor stack body 600S, a current-blocking layer 112, a p-side electrode 613, an adhesion layer 421, a pad electrode 422, and an n-side electrode 114. The semiconductor stack body 600S comprises a substrate 101, a base layer 431, a buffer layer 432, an n-doped cladding layer 402, one or more n-side guide layers, an active layer 605, and a p-side semiconductor layer 600p. The p-side semiconductor layer 600p includes one or more p-side guide layers, first intermediate layer 441, electron blocking layer 409, second intermediate layer 442 and p-side semiconductor outer layer 400u. Semiconductor laser element 600 includes first p-side guide layer 606 and second p-side guide layer 407 as the one or more p-side guide layers. The first n-sided guide layer 403 is a nitride-based semiconductor layer containing Al and provided over an n-doped cladding layer 402. The first n-sided guide layer 403 has a higher average refractive index and a lower average bandgap energy than the n-doped cladding layer 402. The average Al composition ratio of the first n-sided guide layer 403 can be less than 10%. In the present embodiment, the first n-sided guide layer 403 is an n-doped Al0.03Ga0.97N layer with a thickness of 127 nm and doped with Si at an average concentration of 1.0 × 10¹⁸ cm⁻³. Active layer 605 is a light-emitting layer provided above one or more n-sided guide layers. In the present embodiment, active layer 605 is provided above a second n-sided guide layer 404. Active layer 605 is a nitride-based semiconductor layer comprising pot layer 405b and Al-containing barrier layers 405a and 605c, as illustrated in Fig. 12. Barrier layer 605c is a nitride-based semiconductor layer provided above one or more n-sided guide layers and serves as a barrier to the quantum well structure. Barrier layer 605c is provided above barrier layer 405a. In the present embodiment, the average bandgap energy of barrier layer 605c is greater than the average bandgap energy of well layer 405b. In the present embodiment, barrier layer 605c is a layered film of inner barrier layer 605c1 and outer barrier layer 605c2, which is provided above inner barrier layer 605c1 (see Fig. 13). Barrier layer 605c1 is an undoped Al0.04Ga0.96N layer with a thickness of 5 nm. Outer barrier layer 605c2 is a layer with a higher bandgap energy than inner barrier layer 605c1 and has a higher Al composition ratio than inner barrier layer 605c1.The outer barrier layer 605c2 is an undoped Al0.07Ga0.93N layer with a thickness of 3 nm. The first p-side guide layer 606 is a nitride-based semiconductor layer containing Al, located between the active layer 605 and the electron blocking layer 409. In the present embodiment, the first p-side guide layer 606 is arranged beneath the first intermediate layer 441. The first p-side guide layer 606 has a higher average refractive index and a lower average bandgap energy than that of at least one of the n-doped cladding layers 402 or p-doped cladding layers 410. Furthermore, the average bandgap energy of the first p-side guide layer 606 is lower than the average bandgap energy of the second intermediate layer 442 and the average bandgap energy of the barrier layer 605c, which is the highest of the plurality of barrier layers in the active layer 605 (i.e., closest to the electron blocking layer 409). In the present embodiment, the average bandgap energy of the first p-side guide layer 606 is lower than the average bandgap energy of the first intermediate layer 441. For example, an AlGaN layer can be used as the first p-side guide layer 606. The thickness of the first p-side guide layer 606 is, for example, at least 9 nm and at most 60 nm. In the present embodiment, the first p-side guide layer 606 is an undoped Al0.04Ga0.96N layer with a thickness of 9 nm. The p-side electrode 613 is a conductive layer provided over a p-doped contact layer 411. In the present embodiment, the p-side electrode 613 is in contact with the p-doped contact layer 411. The p-side electrode 613 contains at least one of Ag, Al, or Rh. In the present embodiment, the p-side electrode 613 comprises an Ag layer with a thickness of 50 nm and a Pt layer with a thickness of 50 nm, which is provided over the Ag layer. [6-2. Effects] The operating voltage and light loss can also be reduced in semiconductor laser element 600 according to the present embodiment, similarly to semiconductor laser element 400 according to embodiment 4. In the semiconductor laser element 600 according to the present embodiment, the first p-side guide layer 606 consists essentially of AlGaN, and the Al composition ratio of the first p-side guide layer 606 can be less than or equal to the Al composition ratio of the second p-side guide layer 407. For example, since in the present embodiment the Al composition ratio of the second p-side guide layer 407 is 3%, the Al composition ratio of the first p-side guide layer 606 can be 3% or less. Accordingly, the refractive index of the first p-side guide layer 606 can be made greater than or equal to the refractive index of the second p-side guide layer 407, thus reducing the operating voltage and current and increasing the light limiting coefficient, effective refractive index difference and WPE. [Version 7] A semiconductor laser element according to embodiment 7 is described. The semiconductor laser element according to the present embodiment differs from semiconductor laser element 600 according to embodiment 6 primarily in that it does not include a p-side semiconductor outer layer. The semiconductor laser element according to the present embodiment is subsequently described, with the focus on the differences compared to semiconductor laser element 600 according to embodiment 6. [7-1. Overall configuration] A complete configuration of the semiconductor laser element according to the present embodiment is described with reference to Fig. 14. Fig. 14 is a schematic cross-sectional view illustrating a complete configuration of semiconductor laser element 700 according to the present embodiment. Fig. 14 shows a cross-section perpendicular to the Y-axis direction of semiconductor laser element 700, similar to Fig. 2A. As illustrated in Fig. 14, the semiconductor laser element 700 according to the present embodiment comprises a semiconductor stack body 700S, a current-blocking layer 112, a p-side electrode 113, an adhesion layer 421, a pad electrode 422, and an n-side electrode 114. The semiconductor stack body 700S comprises a substrate 101, a base layer 431, a buffer layer 432, an n-doped cladding layer 402, one or more n-side guide layers, an active layer 605, and a p-side semiconductor layer 700p. The p-side semiconductor layer 700p includes one or more p-side guide layers, first intermediate layer 441, electron blocking layer 409 and second intermediate layer 442. Semiconductor laser element 700 includes first p-side guide layer 606, second p-side guide layer 507 and p-doped contact layer 511 as the one or more p-side guide layers. The second p-sided guide layer 507 has the same configuration as the second p-sided guide layer 507 according to embodiment 5. In particular, the second p-sided guide layer 507 is a p-doped Al0.03Ga0.97N layer with a thickness of 50 nm and doped with Mg at an average concentration of 2.0×1019cm-3. P-doped contact layer 511 has the same configuration as p-doped contact layer 511 according to embodiment 5. In particular, p-doped contact layer 511 is a p-doped Al0.03Ga0.97N layer with a thickness of 10 nm and doped with Mg at an average concentration of 2.0×1020cm-3. The P-side electrode 113 has the same configuration as the p-side electrode 113 according to embodiment 4. In particular, the p-side electrode 113 includes an Ag layer with a thickness of 100 nm and a Pt layer with a thickness of 100 nm, which is provided over the Ag layer. [7-2. Effects] Effects similar to those achieved by semiconductor laser element 600 according to embodiment 6 are also achieved in semiconductor laser element 700 according to the present embodiment. In semiconductor laser element 700 according to the present embodiment, the p-side semiconductor layer 700p includes one or more p-side guide layers and the p-side electrode 113 is in ohmic contact with the one or more p-side guide layers. Accordingly, in semiconductor laser element 700, since no layer such as a p-doped cladding layer is provided between the p-side guide layer and the p-side electrode 113, the electrical resistance in the p-side semiconductor layer 700p can be further reduced. Thus, the operating voltage of semiconductor laser element 700 can be lowered even further. [Version 8] A semiconductor laser element according to embodiment 8 is described. The semiconductor laser element according to the present embodiment differs from semiconductor laser element 100 according to embodiment 1 primarily in that the element is a GaAs-based semiconductor laser element and includes a hole-blocking layer. The semiconductor laser element according to the present embodiment is subsequently described, with the focus on the differences compared to semiconductor laser element 100 according to embodiment 1. [8-1. Overall configuration] An overall configuration of the semiconductor laser element according to the present embodiment is described with reference to Figures 15, 16, 17, 18 to 19. Figure 15 is a schematic cross-sectional view illustrating an overall configuration of semiconductor laser element 800 according to the present embodiment. Figure 15 shows a cross-section perpendicular to the Y-axis direction of semiconductor laser element 800, similar to Figure 2A. Figure 16 is a schematic cross-sectional view illustrating a configuration of the hole-blocking layer 840 of semiconductor laser element 800 according to the present embodiment. Figure 17 is a schematic cross-sectional view illustrating a configuration of the active layer 805 of semiconductor laser element 800 according to the present embodiment. Figures 18 and 19 show the active layer 805 of semiconductor laser element 800 according to the present embodiment.Figure 19 are diagrams illustrating configurations of layers other than substrate 801 that are incorporated in semiconductor stack bodies 800S according to the present embodiment. As illustrated in Fig. 15, the semiconductor laser element 800 according to the present embodiment comprises a semiconductor stack body 800S, a current-blocking layer 812, a p-side electrode 813, a pad electrode 822, and an n-side electrode 814. The semiconductor stack body 800S comprises a substrate 801, a buffer layer 832, an interface layer 833, an n-doped cladding layer 802, one or more n-side guide layers, an active layer 805, and a p-side semiconductor layer 800p. Semiconductor laser element 800 includes first n-sided guide layer 803 and second n-sided guide layer 804 as the one or more n-sided guide layers. The p-side semiconductor layer 800p includes an electron blocking layer 809, one or more p-side guide layers and a p-side semiconductor outer layer 800u. Semiconductor laser element 800 includes p-side guide layer 806 as one or more p-side guide layers. The p-side semiconductor outer layer 800u is a semiconductor layer provided above and in contact with one or more p-side guide layers. In the present embodiment, the p-side semiconductor outer layer 800u comprises a p-doped cladding layer 810 and a p-doped contact layer 811. Substrate 801 is a plate-shaped element that serves as the basis for semiconductor laser element 800. In the present embodiment, substrate 801 is an n-doped GaAs substrate with a thickness of 100 µm and doped with an n-doped defect (Si) at an average concentration of 1.0 × 10¹⁸ cm⁻³. The N-side electrode 814 is provided below the lower surface of substrate 801 (the lower main surface in Fig. 15). Buffer layer 832 is an n-doped semiconductor layer provided via substrate 801. In the present embodiment, buffer layer 832 is provided between substrate 801 and interface 833. As illustrated in Fig. 18, buffer layer 832 is an n-doped GaAs layer with a thickness of 0.50 µm and doped with an n-doped impurity (Si) at an average concentration of 3.0 × 10¹⁷ cm⁻³. Interface layer 833 is an n-doped semiconductor layer located between buffer layer 832 and n-doped cladding layer 802. In the present embodiment, interface layer 833 is an n-doped AlXGa1-XAs layer (0.15 ≤ X ≤ 0.29) with a thickness of 0.05 µm and doped with an n-doped impurity (Si) at an average concentration of 2.0 × 10¹⁸ cm⁻³. The Al composition ratio X of interface layer 833 increases with decreasing distance from the n-doped cladding layer 802. The Al composition ratio X of interface layer 833 is 0.15 at the interface with buffer layer 832 and 0.29 at the interface with the n-doped cladding layer 802. N-doped cladding layer 802 is an n-doped semiconductor layer provided via substrate 801. The average refractive index of n-doped cladding layer 802 is lower than the average refractive index of active layer 805. In the present embodiment, n-doped cladding layer 802 is an n-doped Al0.29Ga0.71As layer provided via interface layer 833. In particular, as shown in Fig.Figure 18 illustrates that n-doped cladding layer 802 comprises an n-doped Al0.29Ga0.71As layer with a thickness of 2.50 µm, doped with an n-doped impurity (Si) at an average concentration of 2.0 × 10¹⁸ cm⁻³, an n-doped Al0.29Ga0.71As layer with a thickness of 0.20 µm, doped with an n-doped impurity (Si) at an average concentration of 5.0 × 10¹⁷ cm⁻³ and above that of the previously mentioned layer, an n-doped Al0.29Ga0.71As layer with a thickness of 0.30 µm, doped with an n-doped impurity (Si) at an average concentration of 2.0 × 10¹⁷ cm⁻³ and above that of the previously mentioned layer, and a n-doped Al0.29Ga0.71As layer with a thickness of 0.20 µm, doped with an n-doped impurity (Si) at an average concentration of 1.0×1017cm-3 and provided above the previously mentioned layer. First n-sided guidance layer 803 is an example of an n-sided guidance layer consisting essentially of Alv4Ga1-v4Pw4As1-w4(0 ≤ v4 ≤ 1, 0 ≤ w4 < 1). In the present embodiment, the first n-sided guide layer 803 comprises an n-doped Al0.23Ga0.77As layer with a thickness of 0.56 µm and doped with an n-doped defect (Si) at an average concentration of 3.5 × 10¹⁶ cm⁻³, an n-doped Al0.21Ga0.79As layer with a thickness of 0.32 µm, doped with an n-doped defect (Si) at an average concentration of 3.5 × 10¹⁷ cm⁻³ and provided above the n-doped Al0.23Ga0.77As layer, and an n-doped Al0.15Ga0.85As layer with a thickness of 0.020 µm, doped with an n-doped defect (Si) at an average concentration of 1.0×1017cm-3 and provided above the n-doped Al0,21Ga0,79As layer. Hole-blocking layer 840 is a semiconductor layer provided above n-doped cladding layer 802. Hole-blocking layer 840 has the function of preventing leakage of holes from active layer 805 to first n-sided guide layer 803. In the present embodiment, as illustrated in Fig. 15, hole-blocking layer 840 is provided above first n-sided guide layer 803 and includes first hole-blocking layer 841a, first intermediate layer 842a, second hole-blocking layer 841b, second intermediate layer 842b, third hole-blocking layer 841c, third intermediate layer 842c, fourth hole-blocking layer 841d, fourth intermediate layer 842d, and fifth hole-blocking layer 841e. The first hole-blocking layer 841a is a semiconductor layer provided above an n-doped cladding layer 802 and essentially consists of (Alx1Ga1-x1)y1In1-y1P (0 ≤ x1 ≤ 1, 0 ≤ y1 ≤ 1). In the present embodiment, the first hole-blocking layer 841a is provided above a first n-sided guide layer 803. First intermediate layer 842a is a semiconductor layer provided above first hole-blocking layer 841a and essentially consists of (Alx2Ga1-x2Py2As1-y2(0 ≤ x2 ≤ 1, 0 ≤ y2 < 1). Second hole-blocking layer 841b is a semiconductor layer provided via first intermediate layer 842a and essentially consists of (Alx3Ga1-x3)y3In1-y3P (0 ≤ x3 ≤ 1, 0 ≤ y3 ≤ 1). Second intermediate layer 842b is a semiconductor layer provided via second hole-blocking layer 841b and essentially consists of (Alx4Ga1-x4Py4As1-y4(0 ≤ x4 ≤ 1, 0 ≤ y4 < 1). Third hole-blocking layer 841c is a semiconductor layer provided via second intermediate layer 842b and essentially consists of (Alx5Ga1-x5)y5In1-y5P (0 ≤ x5 ≤ 1, 0 ≤ y5 ≤ 1). Third intermediate layer 842c is a semiconductor layer provided above third hole-blocking layer 841c and essentially consists of (Alx6Ga1-x6Py6As1-y6(0 ≤ x6 ≤ 1, 0 ≤ y6 < 1). Fourth hole-blocking layer 841d is a semiconductor layer provided above third intermediate layer 842c and essentially consists of (Alx7Ga1-x7)y7In1-y7P (0 ≤ x7 ≤ 1, 0 ≤ y7 ≤ 1). Fourth intermediate layer 842d is a semiconductor layer provided above fourth hole-blocking layer 841d and essentially consists of (Alx8Ga1-x8Py8As1-y8(0 ≤ x8 ≤ 1, 0 ≤ y8 < 1). Fifth hole blocking layer 841e is a semiconductor layer provided above fourth intermediate layer 842d and essentially consists of (Alx9Ga1-x9)y9In1-y9P (0 ≤ x9 ≤ 1, 0 ≤ y9 ≤ 1). The average band gap energy of each of first hole-blocking layer 841a, second hole-blocking layer 841b, third hole-blocking layer 841c, fourth hole-blocking layer 841d and fifth hole-blocking layer 841e is greater than the average band gap energy of each of first intermediate layer 842a, second intermediate layer 842b, third intermediate layer 842c and fourth intermediate layer 842d. In the present embodiment, as illustrated in Fig. 18, each of the first hole-blocking layer 841a, second hole-blocking layer 841b, third hole-blocking layer 841c, fourth hole-blocking layer 841d and fifth hole-blocking layer 841e is an n-doped (Al0,12Ga0,88)0,51In0,49P layer with a film thickness of 0.004 µm and with an n-doped defect (Si) at an average concentration of 1.0×1017cm-3. Furthermore, each of the first intermediate layer 842a, second intermediate layer 842b, third intermediate layer 842c and fourth intermediate layer 842d is an n-doped Al0.15Ga0.85As layer with a thickness of 0.004 µm and doped with an n-doped impurity (Si) at an average concentration of 1.0×1017cm-3. The second n-sided guide layer 804 according to the present embodiment is an example of an n-sided guide layer consisting essentially of Alv4Ga1-v4Pw4As1-w4(0 ≤ v4 ≤ 1, 0 ≤ w4 < 1) and provided between hole-blocking layer 840 and active layer 805. In particular, as illustrated in Fig. 18, the second n-sided guide layer 804 is an n-doped Al0.15Ga0.85As layer with a thickness of 0.020 µm and doped with an n-doped defect (Si) at an average concentration of 1.0 × 10¹⁷ cm⁻³. Active layer 805 comprises barrier layer 805a, pot layer 805b provided via barrier layer 805a, and barrier layer 805c provided via pot layer 805b, as illustrated in Fig. 17. As illustrated in Fig. 19, barrier layer 805a according to the present embodiment is an undoped Al0.10Ga0.90As layer with a thickness of 0.025 µm. Pot layer 805b is an undoped In0.135Ga0.865As layer with a thickness of 0.0090 µm. Barrier layer 805c is an undoped Al0.10Ga0.90As layer with a thickness of 0.025 µm. Electron-blocking layer 809 is a semiconductor layer provided between active layer 805 and p-doped cladding layer 810 and acts as a barrier to electrons. In the present embodiment, electron-blocking layer 809 is provided above and in contact with active layer 805. Electron-blocking layer 809 is a p-doped Al0.90Ga0.10As layer with a thickness of 0.020 µm and doped with a p-doped defect (C) at an average concentration of 3.0 × 10¹⁶ cm⁻³. The P-side guide layer 806 consists essentially of Alv3Ga1-v3Pw3As1-w3(0 ≤ v3 ≤ 1, 0 ≤ w3 < 1). In particular, as shown in Fig.As illustrated in Figure 19, p-side guide layer 806 comprises a first layer, which is an undoped Al0.15Ga0.85As layer with a thickness of 0.010 µm; a second layer, which is a p-doped Al0.25Ga0.75As layer with a thickness of 0.020 µm, doped with a p-doped defect (C) at an average concentration of 3.0 × 10¹⁶ cm⁻³ and provided above the first layer; and a third layer, which is a p-doped AlXpGa1-XpAs layer (0.25 ≤ Xp ≤ 0.26) with a thickness of 0.16 µm, doped with a p-doped defect (C) at an average concentration of at least 4.0 × 10¹⁶ cm⁻³ and at most 1.5 × 10¹⁷ cm⁻³ and provided above the second layer is provided, and a fourth layer, which is a p-doped Al0,26Ga0,74As layer with a thickness of 0.10 µm, doped with a p-doped impurity (C) at an average concentration of 3.0×1016cm-3 and is provided above the third layer.In the third layer, the Al composition ratio and the p-doped impurity concentration increase with increasing distance from active layer 805. P-doped cladding layer 810 consists essentially of Alv6Ga1-v6Pw6As1-w6(0 ≤ v6 ≤ 1, 0 ≤ w6 < 1). In particular, as illustrated in Fig. 19, p-doped cladding layer 810 comprises a p-doped Al0.75Ga0.25As layer with a thickness of 0.05 µm and doped with a p-doped defect (C) at a concentration of 1.0 × 10¹⁸ cm⁻³ and a p-doped Al0.85Ga0.15As layer with a thickness of 0.10 µm, doped with a p-doped defect (C) at a concentration of 1.0 × 10¹⁸ cm⁻³, and which is provided above the p-doped Al0.75Ga0.25As layer. As illustrated in Fig. 19, p-doped contact layer 811 is a p-doped GaAs layer with a thickness of 0.10 µm and doped with a p-doped defect (C) at a concentration of 3.0×1019cm-3. Bridge 811R is provided in the second intermediate layer 442 and the p-doped contact layer 811 of semiconductor stack body 800S. Bridge 811R is a part that projects upward from the lower surface 811Tb and extends in the Y-axis direction. Bridge 811R includes the upper surface 811Rt and the side surfaces 811Rs. The side surface 811Rs is a surface that connects the upper surface 811Rt and the lower surface 811Tb of bridge 811R. The side surface 811Rs is in contact with the lower surface 811Tb at the bottom edge of the bridge 811Rb. In the present embodiment, two projecting parts 811P are provided in semiconductor stack bodies 800S. The two projecting parts 811P are parts that project upwards from the lower surface 811Tb and extend in the Y-axis direction. A web 811R is provided between the two projecting parts 811P. Each of the two projecting parts 811P comprises an upper surface 811Pt and a side surface 811Ps. A groove 811T is provided between each of the two projecting parts 811P and the web 811R. Grooves 811T are provided along the web 811R and extend in the Y-axis direction. A side surface 811Ps is a surface that connects the upper surface 811Pt and the lower surface 811Tb of the projecting part 811P. In the present embodiment, the position in the stacking direction of upper surface 811Pt of each projecting part 811P is the same as the position in the stacking direction of upper surface 811Rt of web 811R. In the present embodiment, the lower surface 811Tb and the lower edge of the web 811Rb are located on the uppermost surface of the p-doped shell layer 810 in the stacking direction. Current-blocking layer 812 is an insulating layer provided over p-doped cladding layer 810. In the present embodiment, current-blocking layer 812 is an insulating layer that transmits light from active layer 805. Current-blocking layer 812 is provided over the edge portions of the top surface of bridge 811R and in regions that are not the top surface of bridge 811R within the top surface of semiconductor stack body 800S. In the present embodiment, current-blocking layer 812 is a SiN layer with a thickness of 100 nm. The p-side electrode 813 is a conductive layer provided over a p-doped contact layer 811. In the present embodiment, the p-side electrode 813 is in contact with the p-doped contact layer 811. The p-side electrode 813 contains at least one of Ag, Al, or Rh. In the present embodiment, the p-side electrode 813 includes an Ag layer with a thickness of 200 nm and a Pt layer with a thickness of 100 nm, which is provided over the Ag layer. Pad electrode 822 is a pad-shaped electrode provided above p-side electrode 813. In the present embodiment, pad electrode 822 is provided above p-side electrode 813. In the present embodiment, pad electrode 822 is an Au layer with a thickness of 2.0 µm. N-side electrode 814 is an electrode located beneath the lower surface of substrate 801. The configuration of n-side electrode 814 is not particularly restricted, as long as it is conductive. For example, a layered film can be used as n-side electrode 814, comprising a 90 nm thick AuGe film, a 20 nm thick Ni film, a 50 nm thick Au film, a 100 nm thick Ti film, a 50 nm thick Pt film, a 50 nm thick Ti film, a 100 nm thick Pt film, and a 500 nm thick Au film, stacked in that order on substrate 801. [8-2. Effects] In semiconductor laser element 800 according to the present embodiment, similar to semiconductor laser element 100 according to embodiment 1, the thickness of the p-side semiconductor outer layer 800u of one or more pot layers included in active layer 805 is less than a first distance between pot layer 805b, which is closest to the n-doped cladding layer 802, and the n-doped cladding layer 802 and the p-side electrode 813, which contains at least one of Ag, Al, or Rh. Furthermore, a second distance between pot layer 805, which is closest to the p-side electrode 813, and the p-side electrode 813 can be shorter than the first distance. In addition, the thickness of the p-side semiconductor outer layer 800u can be less than the thickness of the p-side guide layer 806.Here, the thickness of p-side guide layer 806 is an example of the thickness from the p-side guide layer closest to active layer 805 to the p-side guide layer furthest from one or more p-side guide layers. Accordingly, in semiconductor laser element 800 according to the present embodiment, the operating voltage can be reduced and light loss can be decreased, similar to semiconductor laser element 100 according to embodiment 1. The semiconductor laser element 800 according to the present embodiment includes an electron blocking layer which is provided above and in contact with active layer 805. Accordingly, electron leakage from active layer 805 can be prevented. Thus, the light output of semiconductor laser element 800 can be increased by increasing the recombination probability of electrons with holes in active layer 805. The semiconductor laser element 800 according to the present embodiment includes a hole-blocking layer 840, which is provided between an n-doped cladding layer 802 and an active layer 805, and the hole-blocking layer 840 includes a first hole-blocking layer 841a, which essentially consists of (Alx1Ga1-x1)y1In1-y1P (0 ≤ x1 ≤ 1, 0 ≤ y1 ≤ 1), a first intermediate layer 842a, which essentially consists of Alx2Ga1-x2Py2As1-y2(0 ≤ x2 ≤ 1, 0 ≤ y2 < 1), which is provided above the first hole-blocking layer 841a, and a second hole-blocking layer 841b, which essentially consists of (Alx3Ga1-x3)y3In1-y3P (0 ≤ x3 ≤ 1, 0 ≤ y3 ≤ 1) consists of the first intermediate layer 842a, and the average band gap energy of each of the first hole-blocking layer 841a and second hole-blocking layer 841b may be greater than the average band gap energy of the first intermediate layer 842a. Accordingly, the size of the energy barrier in the conduction band of hole-blocking layer 840 can be reduced. Thus, hole-blocking layer 840 can reduce the barrier to electrons in hole-blocking layer 840, while preventing the leakage of holes from active layer 805 to n-doped shell layer 802. Furthermore, two or more hole barriers can be provided by including a first hole-blocking layer 841a, a first intermediate layer 842a, and a second hole-blocking layer 841b. Thus, for example, hole leakage from the active layer 805 to the n-doped cladding layer 802 can be prevented compared to the case where the semiconductor laser element includes a single hole barrier. In hole-blocking layer 840 according to the present embodiment, at least part of the lattice mismatch from first hole-blocking layer 841a to fifth hole-blocking layer 841e with respect to substrate 801 can be compensated by the lattice mismatch from first hole-blocking layer 842a to fourth hole-blocking layer 842d with respect to substrate 801 by adjusting the composition ratio of p in the first intermediate layer 842a to the fourth intermediate layer 842d with respect to substrate 801. Thus, the stress in hole-blocking layer 840 caused by stacking the layers can be reduced. Accordingly, crystal defects in semiconductor laser element 800 can be reduced, and therefore the reliability of semiconductor laser element 800 can be improved. [Version 9] A semiconductor laser element according to embodiment 9 is described. The semiconductor laser element according to the present embodiment differs from semiconductor laser element 400 according to embodiment 4 in that, for example, no protruding part is provided in the semiconductor stack body. The semiconductor laser element according to the present embodiment is subsequently described, with the emphasis on the differences compared to semiconductor laser element 400 according to embodiment 4. [9-1. Overall configuration] A complete configuration of the semiconductor laser element according to the present embodiment is described with reference to Fig. 20. Fig. 20 is a schematic cross-sectional view illustrating a complete configuration of semiconductor laser element 900 according to the present embodiment. Fig. 20 shows a cross-section perpendicular to the Y-axis direction of semiconductor laser element 900, similar to Fig. 2A. As illustrated in Fig. 20, the semiconductor laser element 900 according to the present embodiment comprises a semiconductor stack body 900S, a current-blocking layer 112, a p-side electrode 913, an adhesion layer 921, a pad electrode 922, and an n-side electrode 114. The semiconductor stack body 900S comprises a substrate 101, a base layer 431, a buffer layer 432, an n-doped cladding layer 402, one or more n-side guide layers, an active layer 405, and a p-side semiconductor layer 900p. An element insulation groove 10T is provided in each lateral surface (the end face in the X-axis direction) of the semiconductor stack body 900S. Semiconductor laser element 900 includes first n-sided guide layer 403 and second n-sided guide layer 404 as the one or more n-sided guide layers. The p-side semiconductor layer 900p includes one or more p-side guide layers, first intermediate layer 441, electron blocking layer 409, second intermediate layer 442 and p-side semiconductor outer layer 400u. Semiconductor laser element 900 includes first p-side guide layer 906 and second p-side guide layer 407 as the one or more p-side guide layers. The first p-sided guide layer 906 is a nitride-based semiconductor layer containing Al, located between the active layer 405 and the electron-blocking layer 409. In the present embodiment, the first p-sided guide layer 906 is located beneath the first intermediate layer 441. The first p-sided guide layer 906 has a higher average refractive index and a lower average bandgap energy than that of at least one of the n-doped cladding layers 402 or p-doped cladding layers 410. Furthermore, the average bandgap energy of the first p-sided guide layer 906 is lower than the average bandgap energy of the second intermediate layer 442 and the average bandgap energy of the barrier layer 405c, which is the highest (i.e., closest to the electron-blocking layer 409) of the plurality of barrier layers in the active layer 405.Accordingly, electrical conduction of holes from the p-doped cladding layer 410 to the active layer 405 is easier. Thus, the operating voltage of the semiconductor laser element 900 can be reduced. In the present embodiment, the average band gap energy of the first p-side guide layer 906 is smaller than the average band gap energy of the first intermediate layer 441. An AlGaInN layer can be used as the first p-side guide layer 906. In the present embodiment, the first p-side guide layer 906 is an undoped Al0.04Ga0.947In0.013N layer with a thickness of 20 nm. The p-doped contact layer 411 is a p-doped nitride-based semiconductor layer provided above the p-doped cladding layer 410 and in ohmic contact with the p-side electrode 113. In the present embodiment, the p-doped contact layer 411 comprises a p-doped GaN layer with a thickness of 30 nm and doped with Mg at an average concentration of 2.0 × 10¹⁹ cm⁻³, and a p-doped GaN layer with a thickness of 10 nm, doped with Mg at an average concentration of 2.0 × 10²⁰ cm⁻³, and provided above the aforementioned layer. Bridge 910R is provided in the first p-side guide layer 906, first intermediate layer 441, electron blocking layer 409, second intermediate layer 442, second p-side guide layer 407, p-doped cladding layer 410, and p-doped contact layer 411 of semiconductor stack body 900S. Bridge 910R is a portion that projects upward from the lower surface 910Tb and extends in the Y-axis direction. Bridge 910R includes the upper surface 910Rt and side surfaces 910Rs. Side surface 910Rs is a surface that connects the upper surface 910Rt and the lower surface 910Tb of bridge 910R. Side surface 910Rs is in contact with the lower surface 910Tb at the bottom edge of the bridge 910Rb. In the present embodiment, no protruding part is provided in the semiconductor stack body 900S. The lower surface 910Tb according to the present embodiment is a flat surface extending from the bottom edge of the web 910Rb to the element separation groove 10T. In the present embodiment, the web width W is approximately 15 µm. The lower surface 910Tb and the web lower edge 910Rb are located in the stacking direction between the uppermost surface of the top layer and the lowermost surface of the bottom layer of the one or more p-sided guide layers included in the semiconductor laser element 900. Specifically, the lower surface 910Tb and the web lower edge 910Rb are located in the stacking direction between the uppermost surface and the lowermost surface of the first p-sided guide layer 906, which is the bottommost layer of the one or more p-sided guide layers included in the semiconductor laser element 900. In the present embodiment, the lower surface 910Tb and the web lower edge 910Rb are located 10 nm below the uppermost surface of the first p-sided guide layer 906. Current-blocking layer 112 is an insulating layer provided over p-side semiconductor layer 900p. In the present embodiment, current-blocking layer 112 is transparent to light from active layer 405. As illustrated in Fig. 20, current-blocking layer 112 is provided in regions of the upper surface of semiconductor stack body 900S that are not the upper surface 910Rt of web 910R. In particular, current-blocking layer 112 is provided continuously over side surfaces 910Rs of web 910R, lower surface 910Tb, and element separation grooves 10T. Adhesion layer 921 is a metal layer provided between current-blocking layer 112 and pad electrode 922. Adhesion layer 921 serves to improve the adhesion of pad electrode 922. Adhesion layer 921 is provided over the lower surface 910Tb above current-blocking layer 112. In the present embodiment, adhesion layer 921 is provided over portions of the lower surface 910Tb. Adhesion layer 921 is not provided over or near ridge 910R within the lower surface 910Tb. Thus, adhesion layer 921 is separated from current-blocking layer 112, which is provided over lateral surfaces 910Rs of ridge 910R. In the present embodiment, adhesion layer 921 includes a Ti layer with a thickness of 10 nm provided over the current-blocking layer 112, and a Pt layer with a thickness of 100 nm provided over the Ti layer.It should be noted that in adhesion layer 921, a layer consisting essentially of a material that absorbs laser light, such as Cr or Ni, can be used instead of the Ti layer. The p-side electrode 913 is a conductive layer provided above the p-side semiconductor layer 900p and in ohmic contact with the p-side semiconductor layer 900p. In the present embodiment, the p-side electrode 913 is in ohmic contact with the p-side semiconductor outer layer 400u. As illustrated in Fig. 20, the p-side electrode 913 is provided above the upper surface 910Rt of the bridge 910R of the p-doped contact layer 411 and is continuously provided above the side surfaces 910Rs and the lower surface 910Tb of the bridge 910R via the current-blocking layer 112. In the present embodiment, the p-side electrode 913 is also provided in partial regions between the adhesion layer 921 and the pad electrode 922. The P-side electrode 913 is provided via current blocking layer 112 and in contact with current blocking layer 112, between adhesion layer 921 and lateral surfaces 910Rs of bridge 910R.The P-side electrode 913 contains at least one of Ag, Al or Rh. Pad electrode 922 is a pad-shaped electrode provided via p-side electrode 913. In the present embodiment, pad electrode 922 is provided via p-side electrode 913 and adhesion layer 921. In the present embodiment, pad electrode 922 is an Au layer with a thickness of 2.0 µm. In semiconductor laser element 900 according to the present embodiment, the distance between the lower edge of the bridge 910Rb and the active layer 405 is further reduced compared to semiconductor laser element 400 according to embodiment 4, since the lower edges of the bridge 910Rb are located in the first p-side guide layer 906 between the electron blocking layer 409 and the active layer 405. Furthermore, since the p-side electrode 913, which consists essentially of Ag and has a low refractive index, is provided above the current blocking layer 112 over and near the lateral surfaces 910Rs of the bridge 910R, the effective refractive index difference ΔN can be increased. By increasing the effective refractive index difference ΔN, the proportion of the light distribution present outside of the bridge 910R in the waveguide mode can be reduced. As a result, the generation of light components that flow to substrate 101 is prevented. The p-side electrode 913 is provided above and in contact with the current-blocking layer 112 between the adhesion layer 921 and the lateral surfaces 910Rs of the bridge 910R. In other words, since the p-side electrode 913, which consists essentially of Ag, is provided above and near the lateral surfaces 910Rs of the bridge 910R above the current-blocking layer 112, the distance between the active layer 405 and the p-side electrode 913 is reduced. Consequently, the amount of light spontaneously emitted by the active layer 405 can be increased by the p-side electrode 913, directed back to the active layer 405, and reabsorbed by it. As a result, quantum efficiency is increased, the oscillation threshold can be reduced, and differential efficiency is increased. [Variations and others] The semiconductor laser elements according to the present disclosure have been described above based on the embodiments, but the present disclosure is not limited to the embodiments above. For example, each of the embodiments described above includes an example where the semiconductor laser element is a semiconductor laser element in which two end faces form a resonator, but the semiconductor laser element is not limited to this. For example, the semiconductor laser element can be a superluminescent diode. In this case, the reflectance of an end face of the semiconductor stack included in the semiconductor laser element, with respect to light emitted by the semiconductor stack, can be less than or equal to 0.1%. Such a reflectance can be obtained by providing an antireflective film, which, for example, includes a dielectric multilayer film over the end face.Alternatively, if a structure of obliquely oriented strips is used in which a rib acting as a waveguide intersects the front face at an inclination of at least 5 degrees relative to the direction normal to the face, the proportion of a component that is guided light reflected at the front face and then coupled to the waveguides to become guided light again can be reduced to a small value of at most 0.1%. Furthermore, the semiconductor laser elements according to the embodiments above include an electron blocking layer and a current blocking layer, but these layers are not necessarily included. The present disclosure also includes embodiments resulting from the addition of various modifications that skilled persons may devise to the embodiments, and embodiments obtained by combining elements and functions in the embodiments in any way, as long as the combinations do not deviate from the scope of the present disclosure. [Industrial applicability] The semiconductor laser elements according to the present disclosure are applicable, for example, in light sources for processing machines such as highly efficient high-power light sources. [List of reference symbols] 10T Element separation groove 100, 200, 300, 400, 500, 600, 700, 800, 900 Semiconductor laser element 100F, 100R End face 100p, 200p, 300p, 400p, 500p, 600p, 700p, 800p, 900p p-side semiconductor layer 100S, 200S, 300S, 400S, 500S, 600S, 700S, 800S, 900S Semiconductor stack body 100u, 200u, 400u, 800u p-side semiconductor outer layer 101, 801 Substrate 102, 402, 802 n-doped Shell layer 103, 403, 803 first n-side guide layer 104, 204, 404, 804 second n-side guide layer 105, 205, 405, 605, 805 active layer 105a, 105c, 105e, 205a, 205c, 205e, 405a, 405c, 605c, 805a, 805c barrier layer 105b, 105d, 205b, 205d, 405b, 805b pot layer 106, 206, 306, 406, 606, 906 first p-side guide layer 107, 407, 507 second p-side guide layer 108, 308 third p-side guide layer 109, 409, 809 Electron blocking layer 110, 210, 410, 810 p-doped shell layer 110P, 210P, 308P, 410P, 507P, 811P Projecting part 110Ps, 110Rs, 210Ps, 210Rs, 308Ps, 308Rs, 410Ps, 410Rs, 507Ps507Rs, 811Ps, 811Rs, 910Rs side surface 110Pt, 110Rt, 210Pt, 210Rt, 308Pt, 308Rt, 410Pt, 410Rt, 507Pt, 507Rt, 811Pt, 811Rt, 910Rt top surface 110R, 210R, 308R, 410R, 507R, 811R, 910R web 110Rb, 210Rb, 308Rb, 410Rb, 507Rb, 811Rb, 910Rb web bottom edge 110T, 210T, 308T, 410T, 507T, 811T Nut 110Tb, 210Tb, 308Tb, 410Tb, 507Tb, 811Tb, 910Tb lower surface 111, 211, 311, 411, 511, 811 p-doped contact layer 112, 812 current blocking layer 113, 613, 813, 913 p-side electrode 114, 814 n-side electrode 421, 921 adhesion layer 422, 822, 922 pad electrode 431 base layer 432,832 Buffer layer 441 First intermediate layer 442 Second intermediate layer 605c1 Inner barrier layer 605c2 Outer barrier layer 806 P-side guide layer 833 Boundary layer 840 Hole blocking layer 841a First hole blocking layer 841b Second hole blocking layer 841c Third hole blocking layer 841d Fourth hole blocking layer 841e Fifth hole blocking layer 842a First intermediate layer 842b Second intermediate layer 842c Third intermediate layer 842d Fourth intermediate layer QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature JP 2014-131019

[0003]

Claims

Semiconductor laser element comprising: an n-doped cladding layer; one or more n-sided guide layers provided above the n-doped cladding layer; an active layer provided above the one or more n-sided guide layers; a p-sided semiconductor layer provided above the active layer;and a p-side electrode provided above the p-side semiconductor layer and in ohmic contact with the p-side semiconductor layer, wherein the active layer comprises one or more pot layers, a second distance between the p-side electrode and a pot layer nearest to the one or more pot layers of the p-side electrode is shorter than a first distance between the n-doped cladding layer and a pot layer nearest to the one or more pot layers of the n-doped cladding layer, and the p-side electrode contains at least one of Ag, Al, or Rh. Semiconductor laser element according to claim 1, wherein the p-sided semiconductor layer comprises: one or more p-sided guide layers; and a p-sided semiconductor outer layer provided above the one or more p-sided guide layers and in contact with the one or more p-sided guide layers. Semiconductor laser element according to claim 2, wherein the p-sided semiconductor outer layer has a thickness less than the thickness from a p-sided guide layer closest to the active layer to a p-sided guide layer furthest from one or more p-sided guide layers from the active layer. Semiconductor laser element according to claim 1, wherein the p-side semiconductor layer includes one or more p-side guide layers and the p-side electrode is in ohmic contact with the one or more p-side guide layers. Semiconductor laser element comprising: an n-doped cladding layer; one or more n-sided guide layers provided above the n-doped cladding layer; an active layer provided above the one or more n-sided guide layers; one or more p-sided guide layers provided above the active layer; a p-sided semiconductor outer layer located above and in contact with the one or more p-sided guide layers;and a p-sided electrode provided above the p-sided semiconductor outer layer and in ohmic contact with the p-sided semiconductor outer layer, wherein the p-sided semiconductor outer layer has a thickness less than the thickness from a p-sided guide layer closest to the active layer to a p-sided guide layer furthest from the one or more p-sided guide layers and the p-sided electrode contains at least one of Ag, Al or Rh. Semiconductor laser element comprising: an n-doped cladding layer; one or more n-sided guide layers provided above the n-doped cladding layer; an active layer provided above the one or more n-sided guide layers; one or more p-sided guide layers provided above the active layer; a p-sided semiconductor outer layer located above and in contact with the one or more p-sided guide layers;and a p-sided electrode provided above the p-sided semiconductor outer layer and in ohmic contact with the p-sided semiconductor outer layer, wherein the active layer comprises one or more pot layers, the p-sided semiconductor outer layer has a thickness less than a first distance between the n-doped cladding layer and a pot layer below the one or more pot layers closest to the n-doped cladding layer, and the p-sided electrode contains at least one of Ag, Al, or Rh. Semiconductor laser element according to one of claims 2 to 6, wherein the one or more p-sided guide layers include an inner guide layer provided at a position closest to the active layer. Semiconductor laser element according to claim 7, wherein the one or more p-sided guide layers include an outer guide layer provided at a position closest to the p-sided electrode, and the semiconductor laser element further comprises an electron blocking layer provided between the outer guide layer and the inner guide layer. Semiconductor laser element according to one of claims 2 to 7, wherein a p-side guide layer of the one or more p-side guide layers is an undoped semiconductor layer. Semiconductor laser element according to one of claims 2, 3, 5 and 6, wherein the p-side semiconductor outer layer includes a p-doped contact layer in contact with the p-side electrode. Semiconductor laser element according to one of claims 2, 3, 5, 6 and 10, wherein the p-side semiconductor outer layer includes an electron blocking layer. Semiconductor laser element according to one of claims 2, 3, 5, 6, 10 and 11, wherein the p-side semiconductor outer layer includes a p-doped cladding layer. Semiconductor laser element according to one of claims 1 to 7, 9 and 10, further comprising: an electron blocking layer provided above and in contact with the active layer.

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