Surface-emitting laser device

Abstract

This surface-emitting laser device includes: a light generation layer; a first light reflection layer of a first conductive type; and a second light reflection layer of a second conductive type. The first light reflection layer and the second light reflection layer are disposed so as to sandwich the light generation layer. The light generation layer includes active layers, a first clad layer, a second clad layer, and a tunnel junction layer. The tunnel junction layer is disposed between the first clad layer and the second clad layer that are between two active layers adjacent to each other in a direction from the first light reflection layer to the second light reflection layer. Further, when λ represents the wavelength of a laser beam reflected by the first light reflection layer and the second light reflection layer, the tunnel junction layer is disposed at a position away from the active layers by an optical distance of λ×(2×k2-1) / 4 (where k2 is a natural number).

Description

Surface-emitting laser device

[0001] The present disclosure relates to a surface-emitting laser device.

[0002] Patent Document 1 discloses a surface-emitting laser device, which includes a pair of distributed Bragg reflectors and an active layer interposed between the pair of distributed Bragg reflectors.

[0003] Japanese Patent Application Laid-Open No. 2020-21879

[0004] In the surface-emitting laser device including the active layer and a pair of distributed Bragg reflectors as described above, it is desired to reduce the loss of laser light.

[0005] a first cladding layer of the first conductivity type disposed on the first cladding layer side of each of the active layers; a second cladding layer of the second conductivity type disposed on the second cladding layer side of each of the active layers; and a tunnel junction layer disposed between the first cladding layer and the first cladding layer between two adjacent active layers of the active layers in the direction from the first cladding layer to the second cladding layer. The tunnel junction layer is disposed at an optical distance of λ×(2×k−1) / 4 (k is a natural number) from the active layers, where λ is the wavelength of light reflected by the first cladding layer and the second cladding layer.

[0006] Another aspect of the present disclosure provides a surface-emitting laser device including: a light generating layer; a first light reflecting layer of a first conductivity type and a second light reflecting layer of a second conductivity type disposed on either side of the light generating layer; a semiconductor substrate including a substrate upper surface and a substrate lower surface, the first light reflecting layer being disposed on the substrate upper surface; a first electrode disposed on the substrate lower surface; and a second electrode disposed on the second light reflecting layer; the light generating layer including a plurality of active layers arranged between the first light reflecting layer and the second light reflecting layer in a direction from the first light reflecting layer to the second light reflecting layer; a first cladding layer of the first conductivity type arranged on the first light reflecting layer side with respect to each of the active layers; a second cladding layer of the second conductivity type arranged on the second light reflecting layer side with respect to each of the plurality of active layers; and a current constriction layer provided between the first electrode and the second electrode and having an opening, wherein the current constriction layer is arranged at an optical distance of λ×(2×k3−1) / 4 (k3 is a natural number) away from the plurality of active layers, where λ is the wavelength of light reflected by the first light reflecting layer and the second light reflecting layer.

[0007] According to the surface-emitting laser device of one aspect of the present disclosure, loss of laser light can be reduced.

[0008] FIG. 1 is a schematic plan view showing a surface-emitting laser device according to a first embodiment. FIG. 2 is a schematic cross-sectional view showing the layer structure of the surface-emitting laser device of FIG. 1. FIG. 3 is a cross-sectional view showing an example of the layer structure of the light generating layer and the light reflecting layer of FIG. 2. FIG. 4 is a cross-sectional view showing an example of the relationship between the layer structure of the light generating layer and the light reflecting layer of FIG. 2 and the wavelength. FIG. 5 is a cross-sectional view showing a modification of the relationship between the layer structure of the light generating layer and the light reflecting layer of FIG. 2 and the wavelength. FIG. 6 is a schematic cross-sectional view showing the layer structure of a surface-emitting laser device according to a second embodiment. FIG. 7 is a cross-sectional view showing an example of the relationship between the layer structure of the light generating layer and the light reflecting layer of FIG. 6 and the wavelength. FIG. 8 is a schematic cross-sectional view showing the layer structure of a surface-emitting laser device according to a third embodiment. FIG. 9 is a cross-sectional view showing an example of the relationship between the layer structure of the light generating layer and the light reflecting layer of FIG. 8 and the wavelength.

[0009] Hereinafter, several embodiments of the surface-emitting laser device of the present disclosure will be described with reference to the accompanying drawings. Note that for simplicity and clarity of description, components shown in the drawings are not necessarily drawn to scale. Also, for ease of understanding, hatching lines may be omitted in cross-sectional views. The accompanying drawings merely illustrate embodiments of the present disclosure and should not be considered to limit the present disclosure. Terms such as "first," "second," and "third" in the present disclosure are used merely to distinguish between objects and not to rank the objects.

[0010] The following detailed description includes devices, systems, and methods embodying exemplary embodiments of the present disclosure. This detailed description is merely illustrative in nature and is not intended to limit the embodiments of the present disclosure or the application and uses of such embodiments.

[0011] The phrase "at least one" as used herein means "one or more" of the desired options. As an example, the phrase "at least one" as used herein means "only one option" or "both of two options" when the number of options is two. As another example, the phrase "at least one" as used herein means "only one option" or "any combination of two or more options" when the number of options is three or more.

[0012] First Embodiment (Schematic Configuration of Surface-Emitting Laser Device) FIG. 1 is a schematic plan view showing a surface-emitting laser device.

[0013] The surface-emitting laser device 10 is a semiconductor laser device known as a VCSEL (Vertical Cavity Surface Emitting Laser). The surface-emitting laser device 10 is formed in a substantially rectangular parallelepiped shape.

[0014] The surface-emitting laser device 10 includes a front surface 101, a rear surface 102, and multiple side surfaces 103, 104, 105, and 106. The front surface 101 and the rear surface 102 face in opposite directions. The direction in which the front surface 101 faces is defined as the thickness direction Z. Two axial directions perpendicular to the thickness direction Z and perpendicular to each other are defined as the first direction X and the second direction Y. The surface-emitting laser device 10 of the first embodiment is viewed from the thickness direction Z as a plan view. In one example, the surface-emitting laser device 10 is formed in a rectangular shape in plan view, with its length in the first direction X being longer than its length in the second direction Y. The shape of the surface-emitting laser device 10 in plan view can be arbitrarily changed. The side surfaces 103 and 104 face in opposite directions in the first direction X. The side surfaces 105 and 106 face in opposite directions in the second direction Y.

[0015] The surface-emitting laser device 10 has a first electrode 11 provided on the rear surface 102 of the device and a second electrode 12 provided on the front surface 101 of the device. The first electrode 11 is, for example, an n-type electrode. The second electrode is, for example, a p-type electrode. The first electrode 11 can be provided, for example, on the entire rear surface 102 of the device. The second electrode 12 is, for example, formed in a rectangular shape in a plan view. The second electrode 12 includes electrode portions 12A of the multiple light-emitting portions 13 and a rectangular external connection portion 12C extending along the side surface 106 of the device. A conductor such as a bonding wire is connected to the external connection portion 12C. Note that an external terminal may be connected to the external connection portion 12C, and a conductor such as a bonding wire may be connected to the external terminal.

[0016] The surface-emitting laser device 10 includes a light-emitting unit 13 formed on an element surface 101 and emitting laser light in a thickness direction Z. The surface-emitting laser device 10 of the first embodiment includes a plurality of light-emitting units 13. The light-emitting units 13 are formed at intervals in the first direction X and the Y direction in a plan view. The light-emitting units 13 are arranged inside a frame-shaped second electrode 12. The light-emitting units 13 are arranged at intervals in the first direction X and the second direction Y in a plan view. In one example, the light-emitting units 13 are arranged in a staggered pattern in a plan view. More specifically, the light-emitting units 13 are arranged such that one light-emitting unit 13 is located at each of the three vertices of a triangle (e.g., an equilateral triangle) in a plan view. It can also be said that the light-emitting units 13 are arranged such that one light-emitting unit 13 is located at each of the six vertices of a hexagon (e.g., a regular hexagon) in a plan view. The light emitting units 13 may be arranged in any desired manner, such as in a matrix or in a radial pattern (concentric circles).

[0017] (Layer Structure of Surface-Emitting Laser Device) Fig. 2 is a schematic cross-sectional view showing the layer structure of an exemplary surface-emitting laser device according to the first embodiment, illustrating the layer structure of one light-emitting section 13. Fig. 3 is a cross-sectional view showing an example of the layer structure of the light-generating layer 50, the first light-reflecting layer 30, and the second light-reflecting layer 40.

[0018] 2 , surface-emitting laser device 10 includes a substrate 20, a first light reflecting layer 30, a second light reflecting layer 40, and a light generating layer 50. First light reflecting layer 30, light generating layer 50, and second light reflecting layer 40 are provided on substrate 20. First light reflecting layer 30 is provided on and in contact with substrate 20. Light generating layer 50 is provided on and in contact with first light reflecting layer 30. Second light reflecting layer 40 is provided on and in contact with light generating layer 50.

[0019] In one example, the substrate 20 includes a compound semiconductor material. The substrate 20 includes, for example, a single crystal of a compound semiconductor material that forms a tetragonal crystal system. The compound semiconductor material may be a III-V semiconductor material. The substrate 20 is made of, for example, a GaAs single crystal containing n-type impurities. The n-type impurities may be, for example, Si (silicon). The substrate 20 includes a substrate upper surface 201 and a substrate lower surface 202 that face opposite each other in the thickness direction Z. The substrate lower surface 202 constitutes the device back surface 102.

[0020] The first electrode 11 is provided on the substrate lower surface 202. The first electrode 11 forms ohmic contact with the substrate lower surface 202 of the substrate 20. The first electrode 11 may include multiple electrode films. Alternatively, the first electrode 11 may be composed of a single electrode film. The first electrode 11 may include, for example, Ni (nickel), Au (gold), Ge (germanium), Ti (titanium), In (indium), Zn (zinc), etc. In one example, the first electrode 11 is composed of a stack of an AuGe layer, a Ni layer, and an Au layer. The second electrode 12 may include multiple electrode films. Alternatively, the second electrode 12 may be composed of a single electrode film. The second electrode 12 may include, for example, Au, Ti, etc. In one example, the second electrode 12 is composed of a stack of a Ti layer and an Au layer. The surface-emitting laser device 10 may include a contact layer interposed between the second light-reflecting layer 40 and the second electrode 12 .

[0021] First light reflecting layer 30 and second light reflecting layer 40 are arranged in thickness direction Z to sandwich light generating layer 50. First light reflecting layer 30 is provided on upper surface 201 of substrate 20. Light generating layer 50 is provided on first light reflecting layer 30. Second light reflecting layer 40 is provided on light generating layer 50. Second electrode 12 is provided on second light reflecting layer 40. Second electrode 12 on second light reflecting layer 40 may be formed, for example, in a ring shape.

[0022] The first light reflecting layer 30 is composed of a first conductivity type DBR (Distributed Bragg Reflector) layer. The first conductivity type is, for example, n-type. The first light reflecting layer 30 contains impurities of the first conductivity type. The impurities of the first conductivity type may be, for example, at least one of Si and Te (tellurium). The first light reflecting layer 30 has a refractive index that changes periodically along the thickness direction Z, and resonantly reflects specific wavelength components.

[0023] The first light reflecting layer 30 has a laminated structure in which a first reflecting layer and a second reflecting layer containing Al are laminated. The first reflecting layer and the second reflecting layer have different refractive indices. The first light reflecting layer 30 includes a plurality of first reflecting layers and a plurality of second reflecting layers. The first reflecting layer is an Al layer having an Al composition α1. α１ Ga （１－α１） The second reflective layer may contain As. α２ Ga （１－α２） The first reflective layer may contain As. The Al composition α1 of the first reflective layer may be greater than 0 and equal to or less than 0.2. The Al composition α2 of the second reflective layer may be equal to or greater than 0.85 and equal to or less than 0.97. The reflectivity of a reflective layer containing AlGaAs decreases as the Al composition increases. Therefore, the refractive index of the first reflective layer and the refractive index of the second reflective layer differ from each other.

[0024] The second light reflecting layer 40 is composed of a DBR layer of a second conductivity type. The second conductivity type is, for example, p-type. The second light reflecting layer 40 contains impurities of the second conductivity type. The impurities of the second conductivity type may be, for example, at least one of C (carbon), Zn, and Mg (magnesium). The second light reflecting layer 40 has a refractive index that changes periodically along the thickness direction Z and resonantly reflects specific wavelength components.

[0025] The second light reflecting layer 40 has a laminated structure in which a third reflecting layer and a fourth reflecting layer containing an Al composition are laminated. The third reflecting layer and the fourth reflecting layer have different refractive indices. The second light reflecting layer 40 of the first embodiment includes a plurality of third reflecting layers and a plurality of fourth reflecting layers. The third reflecting layer is an Al layer having an Al composition α3. α３ Ga （１－α３）The fourth reflective layer may contain Al having an Al composition α4. α４ Ga （１－α４） The third reflective layer may contain As. The Al composition α3 of the third reflective layer may be 0.85 or more and 0.97 or less.

[0026] Each light-emitting section 13 of the surface-emitting laser device 10 emits laser light of a specific wavelength component that is reflected by the first light-reflecting layer 30 and the second light-reflecting layer 40 of the respective light-emitting section 13. The wavelength of the laser light is assumed to be λ. It can be said that each light-emitting section 13 generates laser light of wavelength λ due to the first light-reflecting layer 30 and the second light-reflecting layer 40.

[0027] The light generating layer 50 includes a first active layer 51 and a second active layer 52. The first active layer 51 and the second active layer 52 are arranged in this order in the thickness direction Z, i.e., from the first light reflecting layer 30 toward the second light reflecting layer 40. The first active layer 51 and the second active layer 52 may have a quantum well (QW) structure including quantum well layers and barrier layers. The first active layer 51 and the second active layer 52 may have a multi-quantum well (MQW) structure in which quantum well layers and barrier layers are alternately stacked at any period. The quantum well layer may include GaAs, AlGaAs, or InGaAs. The quantum well layer may be undoped. The barrier layer has a band gap larger than that of the quantum well layer.

[0028] The cladding layers 53 and 54 are arranged to sandwich the first active layer 51. The cladding layers 55 and 56 are arranged to sandwich the second active layer 52. The cladding layers 53 and 55 arranged on the first light reflecting layer 30 side of the active layers 51 and 52 are first cladding layers containing impurities of the first conductivity type. The impurities of the first conductivity type may be, for example, Si. The first cladding layers 53 and 55 are made of Al having an Al composition C. Ｃ Ga （１－Ｃ）The cladding layers 54 and 56 arranged on the second light reflecting layer 40 side of the active layers 51 and 52 are second cladding layers containing impurities of the second conductivity type. The impurities of the second conductivity type may be, for example, C. The second cladding layers 54 and 56 are Al cladding layers containing impurities of the second conductivity type having an Al composition C. Ｃ Ga （１－Ｃ） Contains As.

[0029] The light generating layer 50 includes a tunnel junction layer 57. The tunnel junction layer 57 is disposed between adjacent cladding layers in the thickness direction Z, i.e., the second cladding layer 54 and the first cladding layer 55, in which the active layers 51 and 52 are disposed. The tunnel junction layer 57 allows a tunnel current to flow due to the tunnel effect.

[0030] The surface-emitting laser device 10 includes a current confinement layer 61. The current confinement layer 61 may be disposed between the first electrode 11 and the second electrode 12. In the surface-emitting laser device 10 of the first embodiment, the current confinement layer 61 is provided between the second active layer 52 and the second electrode 12. In one example, the current confinement layer 61 is disposed between the second cladding layer 56, which sandwiches the second active layer 52, and the second optical reflecting layer 40. An adjustment layer 56A is provided between the current confinement layer 61 and the second optical reflecting layer 40. The adjustment layer 56A adjusts the position of the current confinement layer 61. The adjustment layer 56A has the same composition as the second cladding layer 56, for example. The current confinement layer 61 confines the current supplied to the active layers 51, 52.

[0031] The current confinement layer 61 includes a current passing portion 611 and a current confinement portion 612. The current passing portion 611 may be made of a material containing Al. For example, the current passing portion 611 may be made of AlAs (Al ｘ Ga （１－ｘ） The current passing portion 611 is made of a material containing As and Al (composition x is 0.95 or more and 1.00 or less). The current passing portion 611 may contain impurities of the second conductivity type. The current passing portion 611 is provided in the inner portion of each light emitting portion 13. For example, in a plan view, the current passing portion 611 is disposed in the center of each light emitting portion 13. For example, the current passing portion 611 is formed in a circular shape in a plan view.

[0032] The current confinement portion 612 has insulating properties. The current confinement portion 612 is made of an oxide layer. The current confinement portion 612 includes an oxide layer containing Al. The oxide layer containing Al is, for example, Al ２ O ３ (alumina). The oxide layer may contain Ga or As. The current confinement portion 612 is disposed on the side of each light-emitting portion 13 relative to the current passing portion 611. For example, in a plan view, the current confinement portion 612 is formed in a ring shape (e.g., annular) surrounding the current passing portion 611. For example, the current confinement portion 612 is formed by oxidizing the periphery of a layer containing AlAs. The film thickness (physical thickness) of the current confinement layer 61 can be, for example, 15 nm or more and 100 nm or less.

[0033] The current confinement layer 61 includes an opening 613 formed by an annular current confinement portion 612. The opening 613 is formed in an arc shape such that the center portion of the current confinement portion 612 in the thickness direction Z bulges toward the current passing portion 611. This current confinement portion 612 confines the current flowing between the first electrode 11 and the second electrode 12 in each light-emitting portion 13. The current flowing between the first electrode 11 and the second electrode 12 passes through the current passing portion 611 inside the opening 613. The regions of the first active layer 51 and the second active layer 52 facing the current passing portion 611 are light-emitting regions. The current confinement layer 61 increases the current density in the active layers 51 and 52. This improves the luminous efficiency of light generated in the active layers 51 and 52.

[0034] The surface-emitting laser device 10 includes an insulating film 71 that covers the light-emitting section 13. In the first embodiment, the insulating film 71 is formed to cover the surface of the first light-reflecting layer 30, the side surfaces of the light-generating layer 50, and the side surfaces of the second light-reflecting layer 40. The insulating film 71 is made of, for example, SiO ２ , silicon oxide such as SiO, SiN (silicon nitride), SiON, ZrO ２ (zirconium oxide) or TiO (titanium oxide). The insulating film 71 includes a covering portion 72 that covers the upper surface of the second light reflecting layer 40 in each light-emitting portion 13. The covering portion 72 covers the upper surface of the second light reflecting layer 40 that is exposed from the second electrode 12.

[0035] (Position of Each Layer in the Light Generating Layer) FIG. 4 is a cross-sectional view showing an example of the relationship between the layer configuration of the light generating layer 50 constituting the light emitting section 13 and the waveform of the laser light LW.

[0036] The waveform of the laser light LW shown in Fig. 4 indicates the electric field intensity of the laser light LW. Note that the waveform of the laser light LW in Fig. 4 is shown as a constant length with respect to the wavelength λ.

[0037] The light generating layer 50 includes a first active layer 51 and a second active layer 52. The optical distance L11 between the first active layer 51 and the second active layer 52 is preferably λ×k1 / 2 (k1 is a natural number). In the surface-emitting laser device 10 of the first embodiment, the optical distance L11 between the first active layer 51 and the second active layer 52 is λ / 2. The first active layer 51 and the second active layer 52 are located at antinode positions of the laser light LW having a wavelength λ reflected by the first optical reflecting layer 30 and the second optical reflecting layer 40.

[0038] The current confinement layer 61 is disposed at a position different from the antinode position of the laser light LW generated by the first light reflecting layer 30, the second light reflecting layer 40, and the active layers 51 and 52. The current confinement layer 61 is preferably disposed at an optical distance of λ×(2×k3−1) / 4 (k3 is a natural number) from the active layers 51 and 52. The light emitting section 13 of the first embodiment includes two active layers 51 and 52 and one current confinement layer 61.

[0039] The optical distance L21 between the current confinement layer 61 and the first active layer 51 closer to the first optical reflection layer 30 is λ×3 / 4. That is, the current confinement layer 61 is located at an optical distance of λ×3 / 4 from the first active layer 51 closer to the first optical reflection layer 30. The optical distance L22 between the current confinement layer 61 and the second active layer 52 closer to the second optical reflection layer 40 is λ / 4. That is, the current confinement layer 61 is located at an optical distance of λ / 4 from the second active layer 52 closer to the second optical reflection layer 40. The active layers 51 and 52 are located at antinode positions of the laser light LW in the light-emitting unit 13. The current confinement layer 61 is located at a node position of the laser light LW. The antinode positions of the laser light LW are positions where the electric field strength is high, and the node positions are positions where the electric field strength is low. Furthermore, if the difference between the current confinement layer 61 and a position that is an optical distance λ×(2×k3−1) / 4 (k3 is a natural number) away from the first active layer 51 is, for example, λ / 8 or less, then the current confinement layer 61 can be said to be located at a position that is an optical distance λ×(2×k3−1) / 4 (k3 is a natural number) away from the active layers 51 and 52, and can be said to be located at a nodal position.

[0040] The tunnel junction layer 57 is disposed at a position with respect to the laser light LW that is different from the antinode position of the laser light LW. The tunnel junction layer 57 is preferably disposed at a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52. For example, the tunnel junction layer 57 is disposed such that a predetermined position within the tunnel junction layer 57 is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52 in the thickness direction of the tunnel junction layer 57. It can be said that the tunnel junction layer 57 is located at a node position of the laser light LW. If the difference between a predetermined position inside the tunnel junction layer 57 and a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52 is, for example, λ / 8 or less, then the tunnel junction layer 57 can be said to be located at a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52, and can be said to be located at a nodal position.

[0041] The tunnel junction layer 57 includes a first tunnel layer 571 of a first conductivity type and a second tunnel layer 572 of a second conductivity type. The second tunnel layer 572 is disposed on the second light reflecting layer 40 side of the first tunnel layer 571. The first tunnel layer 571 and the second tunnel layer 572 are in contact with each other. The first tunnel layer 571 is in contact with the second cladding layer 54. The second tunnel layer 572 is in contact with the first cladding layer 55.

[0042] The first tunnel layer 571 contains impurities of the first conductivity type. The first tunnel layer 571 is doped with the impurities of the first conductivity type at a high concentration. The impurity concentration in the first tunnel layer 571 is, for example, 5×10 １８ cm －３ 5x10 or more ２０ cm －３ The second tunnel layer 572 includes an impurity of the second conductivity type. The second tunnel layer 572 is doped with an impurity of the second conductivity type at a high concentration. The impurity concentration in the second tunnel layer 572 may be, for example, 5×10 １８ cm －３ 5x10 or more ２０ cm －３ The thickness of the first tunnel layer 571 may be, for example, 10 nm or more and 30 nm or less, and the thickness of the second tunnel layer 572 may be, for example, 10 nm or more and 30 nm or less.

[0043] In the first embodiment, the optical distance L31 between the first tunnel layer 571 and the first active layer 51 is λ / 4. That is, it can be said that the first tunnel layer 571 is disposed at a position that is an optical distance of λ / 4 away from the first active layer 51. For example, the first tunnel layer 571 is disposed at a position in the thickness direction of the first tunnel layer 571 such that the center of the first tunnel layer 571 is an optical distance of λ×(2×k2−1) / 4 (k2 is a natural number) away from the first active layer 51. It can be said that the first tunnel layer 571 is located at a node position of the laser light LW. Furthermore, if the difference between the center of the first tunnel layer 571 and a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layer 51 is, for example, λ / 8 or less, then the first tunnel layer 571 can be said to be positioned at a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52, and can be said to be located at a node position.

[0044] Furthermore, the optical distance L32 between the first tunnel layer 571 and the second active layer 52 is λ / 4. That is, it can be said that the first tunnel layer 571 is disposed at a position that is an optical distance of λ / 4 away from the second active layer 52. For example, the first tunnel layer 571 is disposed at a position in the thickness direction of the first tunnel layer 571 such that the center of the first tunnel layer 571 is an optical distance of λ×(2×k2−1) / 4 (k2 is a natural number) away from the second active layer 52. It can be said that the first tunnel layer 571 is located at a node position of the laser light LW.

[0045] (Operation) Next, the operation of the surface-emitting laser device 10 of the first embodiment will be described. The surface-emitting laser device 10 includes a light-generating layer 50, a first light-reflecting layer 30 of a first conductivity type, and a second light-reflecting layer 40 of a second conductivity type, which are arranged to sandwich the light-generating layer 50. The light-generating layer 50 includes active layers 51 and 52, first cladding layers 53 and 55, second cladding layers 54 and 56, and a tunnel junction layer 57. The active layers 51 and 52 are arranged between the first light-reflecting layer 30 and the second light-reflecting layer 40, in a direction from the first light-reflecting layer 30 to the second light-reflecting layer 40. The first cladding layers 53 and 55 are arranged on the first light-reflecting layer 30 side of the active layers 51 and 52, respectively. The second cladding layers 54 and 56 are arranged on the second light-reflecting layer 40 side of the active layers 51 and 52, respectively. The tunnel junction layer 57 is disposed between the second cladding layer 54 and the first cladding layer 55 between two adjacent active layers 51 and 52 in the direction from the first light reflecting layer 30 toward the second light reflecting layer 40. Furthermore, when the wavelength of the laser light LW is λ, the tunnel junction layer 57 is disposed at an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52.

[0046] The tunnel junction layer 57 has an impurity concentration higher than that of the cladding layers 53 to 56. Such a tunnel junction layer 57 is more likely to absorb the laser light LW generated by the active layers 51 and 52 than the cladding layers 53 to 56. Therefore, the tunnel junction layer 57 can cause a loss in the optical intensity of the laser light LW generated by the light emitting unit 13. The higher the electric field intensity of the laser light LW that forms a standing wave, the greater the loss. Therefore, by locating the tunnel junction layer 57 at a position different from the antinode position of the laser light LW, the loss of the laser light LW due to the tunnel junction layer 57 can be reduced.

[0047] Furthermore, by locating the tunnel junction layer 57 at a node position of the laser light LW, i.e., a position where the electric field strength is low, the loss of the laser light LW can be further reduced. The active layers 51 and 52 are located at antinode positions where the electric field strength is highest in the waveform of the laser light LW. Therefore, by locating the tunnel junction layer 57 at a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52, the loss of the laser light LW due to the tunnel junction layer 57 can be further reduced.

[0048] The tunnel junction layer 57 includes a first tunnel layer 571 of a first conductivity type and a second tunnel layer 572 of a second conductivity type. Therefore, the first tunnel layer 571 is more likely to absorb the laser light LW than the second tunnel layer 572. Therefore, by arranging the first tunnel layer 571 at a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52, the loss of the laser light LW due to the tunnel junction layer 57 can be further reduced.

[0049] The surface-emitting laser device 10 of the first embodiment includes a current confinement layer 61 disposed between the second active layer 52 and the second electrode 12. The current confinement layer 61 includes a current confinement portion 612 forming an opening 613, and a current passing portion 611 disposed inside the opening 613. The current passing portion 611 is formed of a material containing AlAs. The second cladding layer 56 between the second active layer 52 and the second optical reflecting layer 40 is made of AlAs having an Al composition A2. Ａ２ Ga （１－Ａ２）As. Therefore, it can be said that the current passing portion 611 has a higher Al composition than the Al composition A2 of the second cladding layer 56. The current passing portion 611 has a low resistance due to a high impurity concentration of second conductivity type impurities (e.g., C, Zn, Mg). Therefore, like the tunnel junction layer 57, the current passing portion 611 is more likely to absorb the laser light LW than the cladding layers 53 to 56. Therefore, the current confinement layer 61 can cause a loss in the optical intensity of the laser light LW generated by the light emitting portion 13. The higher the electric field intensity of the laser light LW that forms a standing wave, the greater the loss. Therefore, by locating the current confinement layer 61 at a position different from the antinode position of the laser light LW, the loss of the laser light LW due to the current confinement layer 61 can be reduced.

[0050] In the surface-emitting laser device 10, the current confinement layer 61 is disposed at an optical distance of λ×(2×k3−1) / 4 (k3 is a natural number) away from the active layers 51 and 52. Therefore, the current confinement layer 61 is disposed at a node position of the laser light LW, that is, at a position where the electric field strength is low. This makes it possible to further reduce the loss of the laser light LW due to the current confinement layer 61.

[0051] (Effects) As described above, surface-emitting laser device 10 provides the following effects. (1-1) Surface-emitting laser device 10 includes light-generating layer 50, and first light-reflecting layer 30 of a first conductivity type and second light-reflecting layer 40 of a second conductivity type, which are arranged to sandwich light-generating layer 50. Light-generating layer 50 includes active layers 51 and 52, first cladding layers 53 and 55, second cladding layers 54 and 56, and tunnel junction layer 57. Therefore, the light intensity of laser light LW emitted from surface-emitting laser device 10 can be improved compared to a surface-emitting laser device that includes a single active layer in the light-generating layer of the light-emitting section.

[0052] (1-2) The active layers 51, 52 are arranged between the first light reflecting layer 30 and the second light reflecting layer 40 in a direction from the first light reflecting layer 30 to the second light reflecting layer 40. The first cladding layers 53, 55 are arranged on the first light reflecting layer 30 side of the active layers 51, 52, respectively. The second cladding layers 54, 56 are arranged on the second light reflecting layer 40 side of the active layers 51, 52, respectively. The tunnel junction layer 57 is arranged between the second cladding layer 54 and the first cladding layer 55 between two adjacent active layers 51, 52 in a direction from the first light reflecting layer 30 to the second light reflecting layer 40. Furthermore, when the wavelength of the laser light LW is λ, the tunnel junction layer 57 is arranged at an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) from the active layers 51, 52.

[0053] By locating the tunnel junction layer 57 at a node position of the laser light LW, i.e., at a position where the electric field strength is low, the loss of the laser light LW can be further reduced. The active layers 51 and 52 are located at antinode positions where the electric field strength is highest in the waveform of the laser light LW. Therefore, by locating the tunnel junction layer 57 at a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52, the loss of the laser light LW due to the tunnel junction layer 57 can be further reduced.

[0054] (1-3) The tunnel junction layer 57 includes a first tunnel layer 571 of a first conductivity type and a second tunnel layer 572 of a second conductivity type. Therefore, the first tunnel layer 571 is more likely to absorb the laser light LW than the second tunnel layer 572. Therefore, by arranging the first tunnel layer 571 at a position that is an optical distance λ×(2×k2−1) / 4 (k2 is a natural number) away from the active layers 51 and 52, the loss of the laser light LW due to the tunnel junction layer 57 can be further reduced.

[0055] (1-4) The surface-emitting laser device 10 of the first embodiment includes a current confinement layer 61 disposed between the second active layer 52 and the second electrode 12. The current confinement layer 61 includes a current confinement portion 612 forming an opening 613, and a current passing portion 611 disposed inside the opening 613. The current passing portion 611 is formed of a material containing AlAs. The second cladding layer 56 between the second active layer 52 and the second optical reflecting layer 40 is made of AlAs having an Al composition A2. Ａ２ Ga （１－Ａ２） As. Therefore, it can be said that the current passing portion 611 has a higher Al composition than the Al composition A2 of the second cladding layer 56. The current passing portion 611 has a low resistance due to a high impurity concentration of second conductivity type impurities (e.g., C, Zn, Mg). Therefore, like the tunnel junction layer 57, the current passing portion 611 is more likely to absorb the laser light LW than the cladding layers 53 to 56. Therefore, the current confinement layer 61 can cause a loss in the optical intensity of the laser light LW generated by the light emitting portion 13. The higher the electric field intensity of the laser light LW that forms a standing wave, the greater the loss. Therefore, by locating the current confinement layer 61 at a position different from the antinode position of the laser light LW, the loss of the laser light LW due to the current confinement layer 61 can be reduced.

[0056] (1-5) In the surface-emitting laser device 10, the current confinement layer 61 is disposed at an optical distance of λ×(2×k3−1) / 4 (k3 is a natural number) from the active layers 51 and 52. Therefore, the current confinement layer 61 is disposed at a node position of the laser light LW, that is, at a position where the electric field strength is low. This makes it possible to further reduce the loss of the laser light LW due to the current confinement layer 61.

[0057] 5 is a schematic cross-sectional view showing the layer structure of a surface-emitting laser device 10A according to a modified example. The surface-emitting laser device 10A according to this modified example is different from the surface-emitting laser device 10 according to the first embodiment in the optical distance L31 between the tunnel junction layer 57 and the first active layer 51. For this reason, the same reference numerals as those used in the surface-emitting laser device 10 according to the first embodiment are used.

[0058] The light generating layer 50A of the light emitting unit 13A includes a first active layer 51 and a second active layer 52. The optical distance L11 between the first active layer 51 and the second active layer 52 is preferably λ×k1 / 2 (k1 is a natural number). In the surface-emitting laser device 10 of the first embodiment, the optical distance L11 between the first active layer 51 and the second active layer 52 is λ. The first active layer 51 and the second active layer 52 are located at antinode positions of the laser light LW.

[0059] In the surface-emitting laser device 10A of this modified example, the optical distance L32 between the tunnel junction layer 57 and the second active layer 52 is λ / 4, as in the first embodiment. On the other hand, the optical distance L31 between the tunnel junction layer 57 and the first active layer 51 is λ×3 / 4. The surface-emitting laser device 10 of this modified example in which the tunnel junction layer 57 is arranged in this manner also achieves the same effects as those of the surface-emitting laser device 10 of the first embodiment.

[0060] 5 shows the optical distance L31 between the tunnel junction layer 57 and the first active layer 51. The optical distance L32 between the tunnel junction layer 57 and the second active layer 52 may be changed. Also, the optical distance L31 between the tunnel junction layer 57 and the first active layer 51 and the optical distance L32 between the tunnel junction layer 57 and the second active layer 52 may be changed. Also, the optical distance L22 between the second active layer 52 and the current confinement layer 61 may be changed.

[0061] Second Embodiment (Layer Structure of Surface-Emitting Laser Device) Fig. 6 is a schematic cross-sectional view showing the layer structure of an exemplary surface-emitting laser device 210 according to a second embodiment, illustrating the layer structure of one light-emitting section 213. Fig. 7 is a cross-sectional view showing an example of the relationship between the layer structure of the light-generating layer 250 constituting the light-emitting section 213 of the surface-emitting laser device 210 of Fig. 6 and the waveform of the laser light LW. In Figs. 6 and 7, the same components as those in the surface-emitting laser device 10 according to the first embodiment are denoted by the same reference numerals. Below, a description of the same components as those in the first embodiment will be omitted, and only components different from those in the first embodiment will be described.

[0062] The surface-emitting laser device 210 of the second embodiment includes two current confinement layers 61 and 62. The first current confinement layer 61 is disposed between the second active layer 52 and the second electrode 12 (12A). In one example, the first current confinement layer 61 is disposed between the second active layer 52 and the second light reflecting layer 40.

[0063] The second current confinement layer 62 can be disposed between the first active layer 51 and the second electrode 12 (12A). In one example, the second current confinement layer 62 can be disposed between the first active layer 51 and the second active layer 52. In the surface-emitting laser device 210 shown in FIG. 6 , the second current confinement layer 62 is disposed between the first active layer 51 and the tunnel junction layer 57. That is, in the surface-emitting laser device 210 of the second embodiment, the current confinement layers 62, 61 are disposed on the second electrode 12 (12A) side of the active layers 51, 52, respectively. An adjustment layer 54A is interposed between the second current confinement layer 62 and the tunnel junction layer 57. The adjustment layer 54A has the same composition as the second cladding layer 54, for example.

[0064] The first current confinement layer 61 includes a first current passing portion 611 and a first current confinement portion 612. The first current passing portion 611 may be made of a material containing Al. For example, the first current passing portion 611 may be made of AlAs (Al ｘ１ Ga （１－ｘ１） The first current passing portion 611 is made of a material containing As and Al (composition x1 is 0.95 or more and 1.00 or less). The first current passing portion 611 may contain impurities of the second conductivity type. The first current passing portion 611 is provided in the inner portion of each light emitting portion 13. For example, in a plan view, the first current passing portion 611 is disposed in the center of each light emitting portion 13. For example, the first current passing portion 611 is formed in a circular shape in a plan view.

[0065] The first current confinement portion 612 has insulating properties. The first current confinement portion 612 includes an oxide layer containing Al. The oxide layer containing Al is, for example, Al ２ O ３The oxide layer may contain Ga or As. The first current confinement portion 612 is disposed on the side of each light-emitting portion 13 relative to the first current passing portion 611. For example, in a plan view, the first current confinement portion 612 is formed in a ring shape (e.g., annular) surrounding the first current passing portion 611. For example, the first current confinement portion 612 is formed by oxidizing the periphery of a layer containing AlAs. The film thickness (physical thickness) of the first current confinement layer 61 can be, for example, 15 nm or more and 100 nm or less.

[0066] The first current confinement layer 61 includes a first opening 613 formed by an annular first current confinement portion 612. The first opening 613 is formed in an arc shape such that the center of the first current confinement portion 612 in the thickness direction Z bulges toward the first current passing portion 611. The first current confinement portion 612 confines the current flowing between the first electrode 11 and the second electrode 12 in each light-emitting portion 13. The current flowing between the first electrode 11 and the second electrode 12 passes through the first current passing portion 611 inside the first opening 613. The region of the second active layer 52 facing the first current passing portion 611 is the light-emitting region. The first current confinement layer 61 increases the current density in the active layer 52, thereby improving the luminous efficiency of light generated in the active layer 52.

[0067] The second current confinement layer 62 includes a second current passing portion 621 and a second current confinement portion 622. The second current passing portion 621 may be formed of a material containing Al. The second current passing portion 621 may be formed of, for example, AlAs (Al ｘ２ Ga （１－ｘ２） The second current passing portion 621 is made of a material containing As and Al (composition x2 is 0.95 or more and 1.00 or less). The second current passing portion 621 may contain impurities of the second conductivity type. The second current passing portion 621 is provided in the inner portion of each light emitting portion 13. For example, in a plan view, the second current passing portion 621 is disposed in the center of each light emitting portion 13. For example, the second current passing portion 621 is formed in a circular shape in a plan view.

[0068] The second current confinement portion 622 has insulating properties. The second current confinement portion 622 is made of an oxide layer. The second current confinement portion 622 includes an oxide layer containing Al. The oxide layer containing Al is, for example, Al ２ O ３ The oxide layer may contain Ga or As. The second current confinement portion 622 is disposed on the side of each light-emitting portion 13 relative to the second current passing portion 621. For example, in a plan view, the second current confinement portion 622 is formed in a ring shape (e.g., annular) surrounding the second current passing portion 621. For example, the second current confinement portion 622 is formed by oxidizing the periphery of a layer containing AlAs. The film thickness (physical thickness) of the second current confinement layer 62 can be, for example, 15 nm or more and 100 nm or less.

[0069] The second current confinement layer 62 includes a second opening 623 formed by an annular second current confinement portion 622. The second opening 623 is formed in an arc shape such that the center of the second current confinement portion 622 in the thickness direction Z bulges toward the second current passing portion 621. This second current confinement portion 622 confines the current flowing between the first electrode 11 and the second electrode 12 in each light-emitting portion 13. The current flowing between the first electrode 11 and the second electrode 12 passes through the second current passing portion 621 inside the second opening 623. The region of the first active layer 51 facing the second current passing portion 621 is the light-emitting region. The second current confinement layer 62 increases the current density in the first active layer 51. This improves the luminous efficiency of light generated in the first active layer 51.

[0070] (Position of Each Layer in the Light-Generating Layer) The waveform of the laser light LW shown in Fig. 7 indicates the electric field intensity. Note that the waveform of the laser light LW in Fig. 7 is shown as a constant length for the wavelength λ.

[0071] The light emitting section 213 includes a first active layer 51 and a second active layer 52. The optical distance L11 between the first active layer 51 and the second active layer 52 is preferably λ×k1 / 2 (k1 is a natural number). In the surface emitting laser device 210 of the second embodiment, the optical distance L11 between the first active layer 51 and the second active layer 52 is λ. The first active layer 51 and the second active layer 52 are located at antinode positions of the laser light LW.

[0072] The first current confinement layer 61 is disposed at a position with respect to the laser light LW that is different from the antinode position of the laser light LW. The first current confinement layer 61 is preferably disposed at a position that is an optical distance λ×(2×k3−1) / 4 (k3 is a natural number) away from the active layers 51, 52. In the surface-emitting laser device 210 of the second embodiment, the optical distance L22 between the first current confinement layer 61 and the second active layer 52 that is closer to the second optical reflecting layer 40 is λ / 4. The optical distance L21 between the first current confinement layer 61 and the first active layer 51 that is closer to the first optical reflecting layer 30 is λ×5 / 4. Furthermore, if the difference between the first current confinement layer 61 and a position that is an optical distance λ×(2×k3−1) / 4 (k3 is a natural number) away from the active layers 51 and 52 is, for example, λ / 8 or less, then the first current confinement layer 61 can be said to be located at a position that is an optical distance λ×(2×k3−1) / 4 (k3 is a natural number) away from the active layers 51 and 52, and can be said to be located at a nodal position.

[0073] The second current confinement layer 62 is disposed at a position with respect to the laser light LW that is different from the antinode position of the laser light LW. The second current confinement layer 62 is preferably disposed at a position that is an optical distance λ×(2×k3−1) / 4 (k3 is a natural number) away from the active layers 51, 52. In the surface-emitting laser device 210 of the second embodiment, the optical distance L42 between the second current confinement layer 62 and the second active layer 52 that is closer to the second optical reflecting layer 40 is λ×3 / 4. The optical distance L41 between the second current confinement layer 62 and the first active layer 51 that is closer to the first optical reflecting layer 30 is λ / 4. Furthermore, if the difference between the second current confinement layer 62 and a position that is an optical distance λ×(2×k3−1) / 4 (k3 is a natural number) away from the active layers 51, 52 is, for example, λ / 8 or less, then the second current confinement layer 62 can be said to be located at a position that is an optical distance λ×(2×k3−1) / 4 (k3 is a natural number) away from the active layers 51, 52, and can be said to be located at a nodal position.

[0074] In the surface-emitting laser device 210 of the second embodiment, the optical distance L32 between the tunnel junction layer 57 and the second active layer 52 is λ / 4, as in the first embodiment. On the other hand, the optical distance L31 between the tunnel junction layer 57 and the first active layer 51 is λ×3 / 4.

[0075] (Effects) As described above, the surface-emitting laser device 210 of the second embodiment provides the following effects.

[0076] (2-1) The surface-emitting laser device 210 of the second embodiment has the same effects as the surface-emitting laser device 10 of the first embodiment. (2-2) In the surface-emitting laser device 210, the light-generating layer 250 of the light-emitting section 213 includes current confinement layers 62, 61 arranged on the second electrode 12 (12A) side of the active layers 51, 52, respectively. The first current confinement layer 61 includes a first current passing portion 611 and a first current confinement portion 612. The region of the second active layer 52 facing the first current passing portion 611 is the light-emitting region. The second current confinement layer 62 includes a second current passing portion 621 and a second current confinement portion 622. The region of the first active layer 51 facing the second current passing portion 621 is the light-emitting region. In this way, the current density in the active layers 51 and 52 can be increased by the current confinement layers 62 and 61 disposed for the active layers 51 and 52, respectively, and therefore the light emission efficiency in the active layers 51 and 52 can be improved.

[0077] Third Embodiment Layer Structure of Surface-Emitting Laser Device FIG. 8 is a schematic cross-sectional view showing the layer structure of an exemplary surface-emitting laser device 310 according to a third embodiment, illustrating the layer structure of one light-emitting section 313. FIG. 9 is a cross-sectional view showing an example of the relationship between the layer structure of the light-generating layer 350 constituting the light-emitting section 313 of the surface-emitting laser device 310 of FIG. 8 and the waveform of the laser light LW. In FIGS. 8 and 9, the same components as those in the surface-emitting laser device 210 according to the second embodiment are denoted by the same reference numerals. In the following, a description of the same components as those in the second embodiment will be omitted, and only components different from those in the second embodiment will be described.

[0078] The surface-emitting laser device 310 of the third embodiment includes two current confinement layers 61, 62. The first current confinement layer 61 is disposed between the second active layer 52 and the second optical reflection layer 40. The second current confinement layer 62 can be disposed between the first active layer 51 and the second electrode 12 (12A). In the surface-emitting laser device 310 of the third embodiment, the second current confinement layer 62 is disposed between the first optical reflection layer 30 and the first active layer 51. An adjustment layer 53A is interposed between the second current confinement layer 62 and the first optical reflection layer 30. The adjustment layer 53A has the same composition as the first cladding layer 53, for example.

[0079] (Position of Each Layer in the Light-Generating Layer) The waveform of the laser light LW shown in Fig. 9 indicates the electric field intensity. Note that the waveform of the laser light LW in Fig. 9 is shown as a constant length for the wavelength λ.

[0080] In the surface-emitting laser device 310 of the third embodiment, the optical distance L11 between the first active layer 51 and the second active layer 52 is λ / 2. The optical distance L22 between the first current constriction layer 61 and the second active layer 52 closer to the second optical reflecting layer 40 is λ / 4. The optical distance L21 between the first current constriction layer 61 and the first active layer 51 closer to the first optical reflecting layer 30 is λ×3 / 4.

[0081] The optical distance L42 between the second current confinement layer 62 and the second active layer 52 closer to the second optical reflection layer 40 is λ×3 / 4. The optical distance L41 between the second current confinement layer 62 and the first active layer 51 closer to the first optical reflection layer 30 is λ / 4.

[0082] The optical distance L32 between the tunnel junction layer 57 and the second active layer 52 is λ / 4, as in the first embodiment. On the other hand, the optical distance L31 between the tunnel junction layer 57 and the first active layer 51 is λ / 4.

[0083] (Effects) As described above, the surface-emitting laser device 310 of the third embodiment has the same effects as the surface-emitting laser device 210 of the second embodiment.

[0084] (Modifications) The above embodiment can be modified, for example, as follows. The above embodiment and each of the following modifications can be combined with each other as long as no technical contradiction occurs. In the following modifications, parts that are common to the above embodiment will be assigned the same reference numerals as in the above embodiment, and their description will be omitted.

[0085] The number of active layers included in the light generating layer 50 may be three or more. In this case, the tunnel junction layer 57 is disposed between two adjacent active layers in the thickness direction Z and between the adjacent second cladding layer and first cladding layer.

[0086] The number of light-emitting portions 13 can be any number equal to or greater than one. The shape of the second electrode 12 shown in FIG. 1 can be changed as appropriate depending on the number, arrangement, etc. of the light-emitting portions 13. The term "on" used in this disclosure includes both the meanings of "on" and "above," unless the context clearly indicates otherwise. Therefore, the expression "a first layer is formed on a second layer" means that in some embodiments, the first layer may be placed directly on the second layer in contact with the second layer, but in other embodiments, the first layer may be placed above the second layer without contacting the second layer. In other words, the term "on" does not exclude a structure in which another layer is formed between the first layer and the second layer.

[0087] The current confinement layer 61 may be located at an optical distance of λ×(2×k2−1) / 4 (k2 is a natural number) from the active layers 51 and 52, and may be located, for example, in the second light reflecting layer 40. Similarly, the current confinement layer 62 may be located in the first light reflecting layer 30.

[0088] The Z-axis direction used in this disclosure does not necessarily have to be the vertical direction, nor does it have to completely coincide with the vertical direction. Therefore, various structures according to this disclosure (for example, the structure shown in FIG. 1 ) are not limited to the "up" and "down" in the Z-axis direction described herein being "up" and "down" in the vertical direction. For example, the X-axis direction may be the vertical direction, or the Y-axis direction may be the vertical direction.

[0089] (Supplementary Notes) The technical ideas that can be understood from the present disclosure are described below. Note that, for the purpose of aiding understanding and not intending to be limiting, the components described in the Supplementary Notes are given the reference symbols of the corresponding components in the embodiments. The reference symbols are shown as examples to aid understanding, and the components described in each Supplementary Note should not be limited to the components indicated by the reference symbols.

[0090] (Supplementary Note 1) A light generating layer (50, 250, 350) comprising: a first light reflecting layer (30) of a first conductivity type (n-type) and a second light reflecting layer (40) of a second conductivity type (p-type) disposed on either side of the light generating layer (50, 250, 350), wherein the light generating layer (50, 250, 350) comprises: a plurality of active layers (51, 52) arranged between the first light reflecting layer (30) and the second light reflecting layer (40) in a direction from the first light reflecting layer (30) to the second light reflecting layer (40); and a first cladding layer (53, 55) of the first conductivity type (n-type) disposed on the first light reflecting layer (30) side of each of the plurality of active layers (51, 52), a second cladding layer (54, 56) of the second conductivity type (p-type) arranged on the second optical reflecting layer (40) side with respect to each of the plurality of active layers (51, 52); and a tunnel junction layer (57) arranged between the second cladding layer (54, 56) and the first cladding layer (53, 55) between two adjacent active layers (51, 52) of the plurality of active layers (51, 52) in a direction from the first optical reflecting layer (30) to the second optical reflecting layer (40), wherein the tunnel junction layer (57) is arranged at an optical distance of λ×(2×k2−1) / 4 (k2 is a natural number) from the plurality of active layers (51, 52), where λ is the wavelength of light reflected by the first optical reflecting layer and the second optical reflecting layer.

[0091] (Supplementary Note 2) The surface-emitting laser device according to Supplementary Note 1, wherein the tunnel junction layer (57) includes: a first tunnel layer (571) of the first conductivity type (n-type); and a second tunnel layer (572) of the second conductivity type (p-type) arranged on the second light reflecting layer (40) side of the first tunnel layer (571), and the first tunnel layer (571) is arranged at an optical distance of λ×(2×k2−1) / 4 (k2 is a natural number) away from the plurality of active layers (51, 52).

[0092] (Supplementary Note 3) The surface-emitting laser device according to Supplementary Note 1 or Supplementary Note 2, comprising: a semiconductor substrate (20) including a substrate upper surface (201) and a substrate lower surface (202), the first light reflecting layer (30) being provided on the substrate upper surface (201); a first electrode (11) provided on the substrate lower surface (202); a second electrode (12) provided on the second light reflecting layer (40); and current confinement layers (61, 62) having openings (613, 623) provided between the first light reflecting layer (30) and the second electrode (12), the current confinement layers (61, 62) being disposed at an optical distance of λ×(2×k3−1) / 4 (k3 is a natural number) away from the plurality of active layers (51, 52).

[0093] (Supplementary Note 4) The surface-emitting laser device according to Supplementary Note 3, wherein the current confinement layer (61, 62) includes a current confinement portion (612, 622) having the opening (613, 623) and a current passing portion (611, 621) within the opening (613, 623).

[0094] (Supplementary Note 5) The surface-emitting laser device according to Supplementary Note 3 or Supplementary Note 4, wherein the current confinement layer (61) is disposed between the active layer (52) of the plurality of active layers (51, 52) that is closest to the second light reflecting layer (40) and the second electrode (12).

[0095] (Supplementary Note 6) The surface-emitting laser device according to Supplementary Note 3 or Supplementary Note 4, wherein the current confinement layer (61, 62) is one of a plurality of current confinement layers (61, 62).

[0096] (Supplementary Note 7) The surface-emitting laser device according to Supplementary Note 6, wherein the current confinement layers (62, 61) are arranged on the second electrode (12) side with respect to each of the active layers (51, 52).

[0097] (Supplementary Note 8) The surface-emitting laser device according to Supplementary Note 6, wherein the plurality of current confinement layers (61, 62) include: a first current confinement layer (61) arranged between the second electrode (12) and an active layer (52) of the plurality of active layers (51, 52) that is closest to the second optical reflection layer (40); and a second current confinement layer (62) arranged between the first electrode (12) and an active layer (51) of the plurality of active layers (51, 52) that is closest to the first optical reflection layer (30).

[0098] (Supplementary Note 9) A semiconductor device comprising: a light generating layer (50, 250, 350); a first light reflecting layer (30) of a first conductivity type (n-type) and a second light reflecting layer (40) of a second conductivity type (p-type) disposed on either side of the light generating layer (50, 250, 350); a semiconductor substrate (20) including a substrate upper surface (201) and a substrate lower surface (202), the first light reflecting layer (30) being disposed on the substrate upper surface (201); a first electrode (11) disposed on the substrate lower surface (202); and a second electrode (12) disposed on the second light reflecting layer (40), wherein the light generating layer (50, 250, 350) comprises: the first cladding layer (53, 55) of the first conductivity type (n-type) arranged on the first light reflecting layer (30) side with respect to each of the plurality of active layers (51, 52); the second cladding layer (54, 56) of the second conductivity type (p-type) arranged on the second light reflecting layer (40) side with respect to each of the plurality of active layers (51, 52); and a current confinement layer (61, 62) provided between the first electrode (11) and the second electrode (12) and having an opening (613, 623), the current confinement layer (61, 62) is disposed at an optical distance of λ×(2×k3−1) / 4 (k3 is a natural number) away from the plurality of active layers (51, 52), where λ is the wavelength of light reflected by the first light reflecting layer and the second light reflecting layer.

[0099] (Supplementary Note 10) The surface-emitting laser device according to Supplementary Note 9, wherein the current confinement layer (61, 62) includes a current confinement portion (612, 622) having the opening (613, 623) and a current passing portion (611, 621) within the opening (613, 623).

[0100] (Supplementary Note 11) The surface-emitting laser device according to Supplementary Note 9 or Supplementary Note 10, wherein the current confinement layer (61) is disposed between the active layer (52) of the plurality of active layers (51, 52) that is closest to the second light reflecting layer (40) and the second electrode (12).

[0101] (Supplementary Note 12) The surface-emitting laser device according to Supplementary Note 9 or Supplementary Note 10, wherein the current confinement layer (61, 62) is one of a plurality of current confinement layers (61, 62).

[0102] (Supplementary Note 13) The surface-emitting laser device according to Supplementary Note 12, wherein the current confinement layers (62, 61) are arranged on the second electrode (12) side with respect to each of the active layers (51, 52).

[0103] (Supplementary Note 14) The surface-emitting laser device according to Supplementary Note 12, wherein the plurality of current confinement layers (61, 62) include: a first current confinement layer (61) arranged between the second electrode (12) and an active layer (52) of the plurality of active layers (51, 52) that is closest to the second optical reflection layer (40); and a second current confinement layer (62) arranged between the first electrode (12) and an active layer (51) of the plurality of active layers (51, 52) that is closest to the first optical reflection layer (30).

[0104] (Supplementary Note 15) The surface-emitting laser device according to any one of Supplementary Note 1 to Supplementary Note 15, wherein the first light reflecting layer (30) contains a material containing at least one of Si and Te as an impurity.

[0105] (Note 16) The first cladding layer (53, 55) and the second cladding layer (54, 56) are Al having an Al composition C. Ｃ Ga （１－Ｃ） 16. The surface-emitting laser device according to claim 1, further comprising As, wherein the Al composition C is 0.2 or more and 0.8 or less.

[0106] (Supplementary Note 17) The surface-emitting laser device according to any one of Supplementary Note 1 to Supplementary Note 17, wherein the second light reflecting layer (40) contains a material containing at least one of C, Zn, and Mg as an impurity.

[0107] The above description is merely illustrative. Those skilled in the art will recognize that many more possible combinations and permutations are possible other than the components and methods (manufacturing processes) listed for the purpose of illustrating the technology of the present disclosure. The present disclosure is intended to embrace all alternatives, modifications, and variations that fall within the scope of the present disclosure, including the claims.

[0108] 10, 10A, 210, 310 Surface-emitting laser device 101 Surface of element 102 Back surface of element 103-106 Side surface of element 11 First electrode 12 Second electrode 12A Electrode portion 12B Peripheral portion 12C External connection portion 13, 213, 313 Light-emitting portion 20 Substrate 201 Upper surface of substrate 202 Lower surface of substrate 30 Light-reflecting layer (first light-reflecting layer) 40 Light-reflecting layer (second light-reflecting layer) 401 Upper surface 50, 50A, 250, 350 Light-generating layer 501 Upper surface 502 Lower surface 51 Active layer (first active layer) 52 Active layer (second active layer) 53 Cladding layer (first cladding layer) 54 Cladding layer (second cladding layer) 55 Cladding layer (first cladding layer) 56 Cladding layer (second cladding layer) 57 Tunnel junction layer 571 First tunnel layer 572 Second tunnel layer 61 Current confinement layer, first current confinement layer 611 Current passing portion, first current passing portion 612 Current confinement portion, first current confinement portion 613 Opening, first opening 62 Second current confinement layer 621 Second current passing portion 622 Second current confinement portion 623 Second opening 71 Insulating film 72 Covering portion λ Wavelength A1 to A4, C Al composition L11 Optical distance L21, L22 Optical distance L31, L32 Optical distance L41, L42 Optical distance LW Laser light X First direction Y Second direction Z Thickness direction

Claims

1. a light generating layer; and a first light-reflecting layer of a first conductivity type and a second light-reflecting layer of a second conductivity type disposed on either side of the light-generating layer; Including, The photogenerating layer comprises: a plurality of active layers arranged between the first light reflecting layer and the second light reflecting layer in a direction from the first light reflecting layer to the second light reflecting layer; a first cladding layer of the first conductivity type disposed on the first light reflecting layer side of each of the active layers; a second clad layer of the second conductivity type disposed on the second light reflecting layer side with respect to each of the plurality of active layers; a tunnel junction layer disposed between the second cladding layer and the first cladding layer between two adjacent active layers among the plurality of active layers in a direction from the first light reflecting layer toward the second light reflecting layer; Including, the tunnel junction layer is disposed at an optical distance of λ×(2×k2−1) / 4 (k2 is a natural number) from the plurality of active layers, where λ is the wavelength of light reflected by the first light reflecting layer and the second light reflecting layer. Surface-emitting laser device.

2. The tunnel junction layer is a first tunnel layer of the first conductivity type; a second tunnel layer of the second conductivity type disposed on the second light reflecting layer side with respect to the first tunnel layer; Including, The first tunnel layer is optically separated from the plurality of active layers by λ× They are arranged at a distance of (2×k2-1) / 4 (k2 is a natural number).

2. The surface-emitting laser device according to claim 1.

3. a semiconductor substrate including a substrate upper surface and a substrate lower surface, the first light reflective layer being provided on the substrate upper surface; a first electrode provided on a lower surface of the substrate; a second electrode provided on the second light-reflecting layer; a current confinement layer provided between the first electrode and the second electrode and having an opening; the current confinement layer is disposed at an optical distance of λ×(2×k3−1) / 4 (k3 is a natural number) from the plurality of active layers; 3. The surface-emitting laser device according to claim 1.

4. the current confinement layer includes a current confinement portion having the opening and a current passing portion within the opening; 4. The surface-emitting laser device according to claim 3.

5. the current confinement layer is disposed between the second electrode and one of the active layers that is closest to the second light reflecting layer.

4. The surface-emitting laser device according to claim 3.

6. 4. The surface-emitting laser device according to claim 3, wherein the current confinement layer is one of a plurality of current confinement layers.

7. 7. The surface-emitting laser device according to claim 6, wherein the current confinement layers are arranged on the second electrode side with respect to the active layers, respectively.

8. The plurality of current confinement layers include a first current confinement layer disposed between the second electrode and an active layer among the plurality of active layers that is closest to the second light reflecting layer; a second current confinement layer disposed between the first light reflecting layer and an active layer among the plurality of active layers that is closest to the first light reflecting layer; Including, 7. The surface-emitting laser device according to claim 6.

9. a light generating layer; and a first light-reflecting layer of a first conductivity type and a second light-reflecting layer of a second conductivity type disposed on either side of the light-generating layer; a semiconductor substrate including a substrate upper surface and a substrate lower surface, the first light reflective layer being provided on the substrate upper surface; a first electrode provided on a lower surface of the substrate; a second electrode provided on the second light-reflecting layer; Including, The photogenerating layer comprises: a plurality of active layers arranged between the first light reflecting layer and the second light reflecting layer in a direction from the first light reflecting layer to the second light reflecting layer; a first cladding layer of the first conductivity type disposed on the first light reflecting layer side of each of the active layers; a second clad layer of the second conductivity type disposed on the second light reflecting layer side with respect to each of the plurality of active layers; a current confinement layer provided between the first light reflecting layer and the second electrode and having an opening; Including, the current confinement layer is disposed at an optical distance of λ×(2×k3−1) / 4 (k3 is a natural number) from the plurality of active layers, where λ is the wavelength of light reflected by the first light reflective layer and the second light reflective layer. Surface-emitting laser device.

10. the current confinement layer includes a current confinement portion having the opening and a current passing portion within the opening; 10. The surface-emitting laser device according to claim 9.

11. the current confinement layer is disposed between the second electrode and one of the active layers that is closest to the second light reflecting layer.

11. The surface-emitting laser device according to claim 9 or 10.

12. 11. The surface-emitting laser device according to claim 9, wherein the current confinement layer is one of a plurality of current confinement layers.

13. 13. The surface-emitting laser device according to claim 12, wherein the current confinement layers are arranged on the second electrode side with respect to the active layers, respectively.

14. The plurality of current confinement layers include a first current confinement layer disposed between the second electrode and an active layer among the plurality of active layers that is closest to the second light reflecting layer; a second current confinement layer disposed between the first light reflecting layer and an active layer among the plurality of active layers that is closest to the first light reflecting layer; Including, The surface-emitting laser device according to claim 12.