Laser diode with integrated thermal aperture

Abstract

This invention relates to a diode laser with integrated thermal holes. The laser diode (10) according to the invention includes an active layer (14) formed between an n-type doped semiconductor material (12) and a p-type doped semiconductor material (16), wherein the active layer (14) forms an active region (40) along a longitudinal axis, the active region (40) having a width w and being used to generate electromagnetic radiation; wherein, in the p-type doped semiconductor material (16) and / or the n-type doped semiconductor material (12), layered thermal holes (18) with thermal conductivity k are formed. block The thermal conductivity k is less than that of the corresponding semiconductor materials (16, 12). bulk , for spatially selective heat transfer from the active region (40) to the side of the corresponding semiconductor material (16, 12) opposite to the active layer (14).

Description

Technical Field

[0001] This invention relates to a laser diode with an integrated thermal aperture. Background Technology

[0002] Large-area diode lasers (BALs) can exhibit exceptionally high efficiency and brightness. Using these emitters, output power >15W can be reliably achieved. BALs are the most efficient source of near-infrared (NIR) radiation, and therefore they are widely used as pump sources for both solid-state and fiber lasers. They are also key components of fiber-coupled laser systems designed to provide high-radiation beams for material processing with high wall-plug efficiencies. To increase the output power of these systems and reduce their cost, it is important to improve the slow-axis beam quality, as this allows for the coupling of a larger number of emitters in low numerical aperture (NA) fibers.

[0003] However, at high optical output power and associated operating current, beam quality typically degrades significantly, which has a particularly detrimental effect on coupling within the fiber. Studies have shown that thermal lensing in the slow axis (rather than charge carrier or gain-induced guidance) is one of the main causes of beam quality degradation with increasing operating current (Bai, J. Get al, Mitigation of Thermal Lensing Effect as a Brightness Limitation of High-Power Broad Area Diode Lasers, Proc. SPIE 7953, 79531F (2011)). Therefore, the decisive factor in beam quality degradation at high output power is the transverse temperature gradient formed by the increased temperature in the central region under the laser stripe, which leads to a local increase in refractive index, resulting in additional transverse waveguides and thus a larger divergence angle.

[0004] In particular, to improve heat transfer, lengthening the laser resonator or influencing the heat flow between the laser diode and the substrate has been proposed (thermal path techniques; see, for example, Bai et al., DE 10 2013 114226B4 and US2016 0315446A1). This can reduce the lateral temperature gradient, thereby flattening the resulting thermal lens. However, diode lasers with longer resonators have higher manufacturing costs. Recently, however, it has been shown that a high thermal barrier forms at the interface between the laser diode and appropriate metallization, which significantly reduces the effectiveness of thermal path techniques for thermal lensing (Rieprich, J. et al., Chip-carrier thermal barrier and its impact on lateral thermal lens profile and beam parameter product in high power broad area lasers, J. Appl. Phys. 123, 125703 (2018)).

[0005] Another method to reduce the lateral temperature gradient is to additionally heat the laser diode with an external heat source (Hohimer, JP, Mode control in broad area diode lasers by thermally induced lateral index tailoring, Appl. Opt. Phys. Lett. 52, 260 (1988)). However, integrating an external heat source into the diode laser is very complex and therefore impractical.

[0006] The reduction of the transverse temperature gradient can also be achieved through specially adjusted layered structures (Winterfeldt, M. et al., Assessing the Influence of the Vertical Epitaxial Layer Design on the Lateral Beam Quality of High-Power Broad Area Diode Lasers, Proc. SPIE 9733, 97330O (2016)). However, such adjustments only slightly improve the transverse beam quality. Furthermore, this adjustment is only possible in certain laser designs. Summary of the Invention

[0007] Therefore, the object of the present invention is to provide a laser diode in which the lateral temperature gradient can be reduced and the resulting thermal lens can be flattened. In particular, the laser diode does not require any external heat source or adjustment of the layer structure (e.g., metallization) outside the chip, i.e., it is based solely on a monolithic integrated structure within the diode laser.

[0008] According to the invention, these objectives are achieved by the features of claim 1. Suitable embodiments of the invention are included in the corresponding dependent claims.

[0009] The laser diode according to the present invention includes an active layer formed between an n-type doped semiconductor material and a p-type doped semiconductor material, the active layer forming an active region of width w along the longitudinal axis for generating electromagnetic radiation; wherein, in the p-type doped semiconductor material, a thermal conductivity k is formed. block The thermal conductivity k of p-type doped semiconductor materials is less than that of p-type doped semiconductor materials. bulk Layered thermal holes (e.g., in p-type doped semiconductor material between the active region and the cooled lower side of the laser diode) are used for spatially selective heat transfer from the active region to the side of the p-type doped semiconductor material opposite to the active layer; or in n-type doped semiconductor material, thermally conductive holes with a thermal conductivity k are formed. block The thermal conductivity k of the n-type doped semiconductor material is less than that of the n-type doped semiconductor material. bulk The layered thermal holes are used for spatially selective heat transfer from the active region to the side of the n-type doped semiconductor material opposite to the active layer.

[0010] Therefore, the hot holes according to the invention can be formed in both p-type doped semiconductor materials and n-type doped semiconductor materials, with preference given to those semiconductor materials. In the following, p-side hot holes are assumed to be examples, but the explanation applies accordingly to n-side hot holes.

[0011] A laser diode is understood as a layered structure composed of semiconductor materials, with or without metallization (so-called laser chips). The term semiconductor material is generally used here to refer to any semiconductor material or combination of semiconductor materials, such as a combination of AlInGaAsNSb material systems. Specifically, n-type doped semiconductor materials and p-type doped semiconductor materials can also each comprise layered systems of corresponding semiconductor materials of different types or different doping levels with different compositions. Therefore, this usage is understood to be synonymous with the terms n-side semiconductor materials and p-side semiconductor materials.

[0012] An active layer is formed in the transition region between the n-type and p-type doped semiconductor materials. Electromagnetic radiation is generated in the electrically pumped region of the active layer within the active region. Most of the heat generated during laser diode operation is produced there, and this heat must be dissipated accordingly. This is specifically achieved through a base, for example, the base can be thermally connected to the underside of the laser diode below the active region. The connection between the underside of the laser diode and the base is prior art and can be achieved, specifically, by welding or gluing.

[0013] According to the present invention, the thermal conductivity k block The thermal conductivity k of the surrounding p-type doped semiconductor material is less than that of the surrounding p-type doped semiconductor material. bulk A layered hot hole is formed in the p-type doped semiconductor material below the active region for spatially selective heat transfer from the active region to the underside of the laser diode. Thermal conductivity (also called thermal conductivity coefficient) determines the heat flow through a material based on thermal conduction. The lower the value, the worse the thermal conductivity of the material. According to the invention, the hot hole aims to reduce the lateral temperature gradient (i.e., flatten the thermal lens) by locally increasing the thermal resistance in the conventionally widened region (laterally below the active region) in the lateral direction to counteract the spatial lateral widening of the heat flow in the region between the active region and the underside of the laser diode. As a result of its increased thermal resistance, more heat is generated within the strip (in the central region) as the output power increases, leading to a localized temperature rise in the side regions (hot holes). This corresponds to a lower thermal gradient between the central and side regions, thus corresponding to a flatter thermal lens.

[0014] Regarding the relationship between the two thermal conductivity coefficients, the thermal conductivity k of the p-type doped semiconductor material below the active region... bulk This is particularly important. In the case of a p-type doped semiconductor material consisting of several layers, each layer can have a slightly different thermal conductivity k. layer Thermal conductivity k bulk The thermal conductivity can be considered as a result of the thermal flow across all layers involved. As an approximation, the average thermal conductivity of the p-type doped semiconductor material below the active region can also be used as the thermal conductivity k of the p-type doped semiconductor material. bulk Alternatively, as an approximation, the thermal conductivity k of p-type doped semiconductor materials... bulk It can also be equal to the thermal conductivity k of the p-contact layer of the p-type doped semiconductor material. KS .

[0015] Therefore, the present invention specifically aims to achieve a flat thermal lens by directly integrating a monolithically integrated thermal aperture (internal thermal path technology) into the laser diode. Conversely, external thermal path technologies are less effective due to the presence of the intrinsic semiconductor-metal thermal barrier. The thermal aperture according to the invention can also be placed very close to the active region, thereby minimizing the widening of heat flow in the lateral direction and producing a particularly flat thermal lens. Thus, known thermal path technologies in the prior art can be applied within laser diodes, significantly improving their effectiveness and efficiency.

[0016] Preferably, the thermal holes are made of a semiconductor material. This should have a particularly low thermal conductivity (for low thermal conductivity k...). block Furthermore, high electrical conductivity is preferred. In particular, the thermal hole can be constructed from the same semiconductor material system as the p-type doped semiconductor material (e.g., in the case of an AlInGaAsP composite on a GaAs substrate: GaAs and AlGaAs as p-type semiconductor materials). The thermal conductivity k can be reduced by changing the indium and / or phosphorus content. block (For example, in the case of an AlInGaAsP composite on a GaAs substrate: GaAs and AlGaAs are p-type semiconductor materials, and InGaP or InGaAsP is a thermal hole).

[0017] Preferably, in order to achieve a particularly small thermal conductivity k block The thermal holes are formed by periodically alternating materials (e.g., different semiconductors or semiconductor and air), with a large number of regular alternations between the materials, resulting in a thermal conductivity k. layer Many interfaces differ significantly. Heat transfer between interfaces is limited, resulting in a decrease in thermal conductivity k. block Further reduction (see J. Piprek et al, Thermal conductivity reduction in GaAs-AlAs distributed Bragg reflectors, in IEEE Photon.Tech.Lett.10,81(1998)).

[0018] Preferably, thermal holes can be realized using photonic crystal structures. Photonic crystal structures are understood as three-dimensional periodic nanostructures that can influence the movement of photons within a crystal lattice. Typically, to produce high refractive index contrast, openings (“pores”) filled with air or other materials with particularly low refractive indices are formed in the structure. These openings and the transition between multiple materials result in a significant reduction in the thermal conductivity of these materials. In summary, photonic crystal structures can be used to create regions with good optical properties and very low thermal conductivity. The same applies to one-dimensional periodic lattices (superlattices), where thin layers of two different materials, particularly semiconductor materials, are alternately arranged on top of each other.

[0019] With the laser diode according to the invention, the optical properties of the region below the active region can therefore be largely preserved, despite the presence of additional thermal apertures.

[0020] For example, for GaAs(k) KS ≈44W / (m·K)) or Al x Ga 1-x As(k KS A laser diode with approximately 11-91 W / (m·K) can be used to construct InGaP(k) laser diodes. block ≈5W / (m·K)), InGaAsP(k block ≈5W / (m·K)), InGaAsSb or InGaP-InGaAsP superlattice (k block The hot hole is approximately 2.5 W / (m·K).

[0021] To achieve sufficient aperture effect, the thermal conductivity k... block It should be as low as possible. Thermal conductivity k block Preferably, it should be the corresponding bulk value k. bulk The thermal conductivity k can be achieved by utilizing an InGaP-InGaAsP superlattice, with a maximum of 30%, more preferably up to 10%, even more preferably up to 5%, and particularly preferably up to 1%. block It is approximately half the thermal conductivity k-value of InGaP and InGaAsP (see J. Piprek et al., Thermal conductivity reduction in GaAs-AlAs distributed Bragg reflectors, in IEEE Photon. Tech. Lett. 10, 81 (1998)). However, much lower thermal conductivity can be achieved through photonic crystal structures.

[0022] Preferably, the hot holes form a gap-shaped channel region arranged parallel to the active layer to guide heat flow from the active region toward the outer side of the laser diode (e.g., the lower p-side where a heat sink is located in the case of p-side hot holes). In this arrangement, the hot holes can confine the heat flow along the entire resonator axis (z-axis) to the slit-shaped channel. For efficiency reasons, a center-symmetrical arrangement (intermediate arrangement) of the slit-shaped channel region relative to the active region is preferred.

[0023] Preferably, the lateral distance dx between the outer edge of the active region (the lateral boundary in the lateral direction) and the nearest inner edge of the hot hole (the lateral boundary in the lateral direction pointing towards the active region) is -w / 6 ≤ dx ≤ +w / 6. This means that this distance preferably depends on the width w of the active region and is chosen such that the inner edge of the hot hole can have both positive and negative lateral distances to the outer edge of the active region. Particularly preferred is a distance dx of 0, i.e., when the outer edge of the active region and the corresponding inner edge of the hot hole spatially coincide when projected onto the underside of the laser diode.

[0024] Preferably, the vertical distance dy between the center of the active layer and the top of the hot hole is 0 μm ≤ dy ≤ 1 μm. This means that the top of the hot hole is preferably located directly below the center of the active layer, and at most 1 μm away from it. The smallest possible distance has the highest aperture effect, but it will have a negative impact on optical properties. At distances greater than 1 μm, the lateral broadening of heat flow may no longer be effectively suppressed.

[0025] Preferably, the thermal pore has a pore diameter and thickness d between 0.3 μm and 3 μm. block Thicker thermal pores can provide greater suppression of lateral widening of heat flow.

[0026] Preferably, the p-type doped semiconductor material (with integrated thermal holes) has a total layer thickness d between 0.5 μm and 10 μm, more preferably between 1 μm and 5 μm, and even more preferably between 2 μm and 3 μm.

[0027] Preferably, hot holes are formed in layers in both the n-type doped semiconductor material and the p-type doped semiconductor material. The hot holes in the n-type doped semiconductor material can functionally correspond to those in the p-type doped semiconductor material. In this regard, all information provided herein regarding the hot holes in the p-type doped semiconductor material is applicable, taking into account variations in doping. Preferably, the hot holes in the n-type and p-type doped semiconductor materials can be constructed symmetrically with respect to the active layer. This symmetry may specifically refer to the geometry and / or material composition of the hot holes. However, for example, if the p-type and n-type doped semiconductor materials have different thicknesses and the distance needs to be adjusted, the configuration of the hot holes can also differ. Such embodiments are advantageous when the laser diode is mounted for dual-sided cooling, i.e., when heat can be dissipated from both sides of the laser diode.

[0028] Further preferred embodiments of the invention arise from the features mentioned in the dependent claims.

[0029] The various embodiments of the invention mentioned in this application can be advantageously combined with each other, unless otherwise specified in individual cases. Attached Figure Description

[0030] The invention will now be explained with reference to the accompanying drawings and examples of embodiments, wherein:

[0031] Figure 1 This is a schematic diagram of an exemplary conventional laser diode without a hot hole.

[0032] Figure 2 This is a schematic diagram of an exemplary first embodiment of a laser diode with a thermal aperture according to the present invention.

[0033] Figure 3 It simulates the temperature variation within the active region with lateral position (x-axis).

[0034] Figure 4 The thermal conductivity k of the contact layer with respect to p KS Simulation of the varying normalized thermal lens curvature factor |B2|

[0035] Figure 5 For the thickness d of the aperture block Simulation of the varying normalized thermal lens curvature factor |B2|

[0036] Figure 6 This is a simulation of the normalized thermal lens curvature factor |B2| as a function of the lateral distance dx.

[0037] Figure 7 It is for those with a basis Figure 4 The structure of the KS material, the temperature T varying with lateral position (x-axis) and the peak temperature T at position x = 0. peak Simulation of the temperature difference ΔT between them, and

[0038] Figure 8 This is a schematic diagram of an exemplary second embodiment of a laser diode having two hot holes according to the present invention. Detailed Implementation

[0039] Figure 1 A schematic diagram of an exemplary conventional laser diode without hot holes is shown. The illustrated diode laser includes: a laser diode 10 having an active layer 14 formed between an n-type doped semiconductor material 12 and a p-type doped semiconductor material 16, the active layer 14 forming an active region 40 of width w along a longitudinal axis for generating electromagnetic radiation; and a base 30, wherein the base 30 is thermally connected to the lower p-side of the laser diode 10 located below the active region 40. The thermally conductive connection may be formed by an intermediate solder layer 20, wherein the solder is designed to provide optimal heat transfer between the lower side of the laser diode 10 and the base 30.

[0040] Specifically, the laser diode 10 may have a multilayer structure, which includes an n-substrate, an n-cladding covering the n-substrate, an n-waveguide layer covering the n-cladding, an active layer 14 covering the n-waveguide layer, a p-waveguide layer covering the active layer 14, a p-cladding covering the p-waveguide layer, a p-contact layer covering the p-cladding, and a metal p-contact covering the p-contact layer.

[0041] The heat loss that occurs in the active region 40 during laser diode operation must be dissipated from the active region 40. For this purpose, a base 30 is typically used as a corresponding heat sink. However, the heat flow guided from the active region 40 to the base 30 diffuses strongly in the lateral direction, resulting in an uneven temperature distribution in the region below the active region 40. This resulting temperature distribution can produce a thermo-optical effect on the generated electromagnetic radiation and, by forming a thermal lens in this region, cause a deterioration in beam quality during radiation emission.

[0042] Figure 2 A schematic diagram of an exemplary first embodiment of a laser diode with a hot hole according to the present invention is shown. The illustrated diode laser includes: a laser diode 10 having an active layer 14 formed between an n-type doped semiconductor material 12 and a p-type doped semiconductor material 16, the active layer 14 forming an active region 40 of width w along a longitudinal axis (z-axis) for generating electromagnetic radiation; and a base 30, wherein the base 30 below the active region 40 is thermally connected to the lower p-side of the laser diode 10. This corresponds as closely as possible to... Figure 1 The structure described.

[0043] However, in the p-type doped semiconductor material 16, a thermal conductivity k is formed. block The thermal conductivity k is less than that of the p-type doped semiconductor material 16 (below the active region 40). bulk The layered thermal holes 18 are used for spatially selective heat transfer from the active region 40 to the side of the p-type doped semiconductor material 16 opposite to the active layer 14 (below the laser diode 10) and thus to the substrate 30. Approximately, the average thermal conductivity of the p-type doped semiconductor material 16 can also be used as the thermal conductivity k of the p-type doped semiconductor material below the active region 40. bulk Alternatively, the thermal conductivity k of p-doped semiconductor material 16 bulk It can also be approximated by the thermal conductivity k of the p-contact layer of the p-type doped semiconductor material 16. KS .

[0044] Furthermore, the thermally conductive connection can be formed by an intermediate solder layer 20, which is designed to achieve optimal heat transfer between the underside of the laser diode 10 and the base 30. The connection can also be achieved by bonding, for example, using a thermally conductive adhesive.

[0045] Hot aperture 18 forms a slit-shaped channel region arranged parallel to the active layer 14 for guiding heat flow 42 from the active region 40 toward the lower side of the laser diode 10. The slit-shaped channel region is located below the center of the active region 40 in the figure. The propagation of heat flow 42 from the active region 40 to the base 30 in the lateral direction is suppressed by the hot aperture 18 according to the invention, resulting in a generally parallel heat flow 42. As the output power increases, the active region 40 generates more heat, and the high thermal resistance of the hot aperture 18 leads to an increase in its local temperature (i.e., heating in the lateral region). This results in a more uniform temperature distribution in the region below the active region 40 between the central region (directly below the active region) and the hot aperture (side region). Therefore, the formation of thermal lenses in this region is also suppressed, which can improve beam quality during radiative emission.

[0046] The figure further shows the horizontal distance dx between the outer edge of the active region 40 and the nearest inner edge of the hot hole. It also shows the vertical distance dy between the center of the active layer 14 and the hot hole 18. The aperture thickness d of the hot hole 18 is also shown. block The total layer thickness d of the p-type doped semiconductor material 16.

[0047] This description applies accordingly to the hot hole 18 formed in the n-type doped semiconductor material 12. In this case, the corresponding base 30 above the active region 40 can be thermally connected to the top of the n-side of the laser diode 10 to suppress the lateral widening of the upwardly directed heat flow 42.

[0048] Figure 3 Simulations of temperature variation within the active region with lateral position (x-axis) are presented. These simulations are performed at the vertical position (y-axis) where y = 0, i.e., at the center of the active layer, for a large-area diode laser (BAL) based on GaAs with a stripe width w = 90 μm (see M. Elattar et al, High-brightness broad-area diode lasers with enhanced self-aligned lateral structure, Semicond. Sci. Technol. 35, 095011 (2020)), with an optical power P opt Operating at 10W. The simulated BAL corresponds to a typical structure consisting of an active region (AZ) between n-type and p-type doped semiconductor materials. The p-type doped semiconductor material is composed of Al grown on the AZ. x Ga 1-x As waveguide layer (WL), followed by Al x GaA 1-xThe simulation consists of an As cladding layer (MS) and a final GaAs contact layer (KS), upon which a contact metal is subsequently deposited. The simulation (matching corresponding experimental results) includes a thermal barrier at the KS metal interface. The term thermal lens curvature factor B2 is a quadratic term of the quadratic fit to the obtained thermal profile (Rieprich, J. et al., Chip-carrier thermal barrier and its impact on lateral thermal lens profile and beam parameter product in high power broad area lasers, J. Appl. Phys. 123, 125703 (2018)), where a quadratic fit was performed on a region within a strip width w = 90 μm in the simulation. An exemplary conventional diode laser in the simulation shows that a thermal profile with a curved profile between approximately 45°C at the edges of the broad strip and approximately 51°C at the center was obtained.

[0049] Figure 4 The thermal conductivity k of the p-contact layer is shown. KS Simulation of the varying normalized thermal lens curvature factor |B2|. In the reference structure, KS is composed of GaAs (kKS ≈ 44 W / (m·K)). When GaAs is replaced by a material with lower thermal conductivity, such as InGaP (k block ≈5W / (m·K)), InGaAsP(k block ≈5W / (m·K)), InGaP-InGaAsP superlattice (k block ≈2.5 W / (m·K); see J. Piprek et al., Thermal conductivity reduction in GaAs-AlAs distributed Bragg reflectors, in IEEE Photon. Tech. Lett. 10, 81 (1998)), or air (k air When the normalized thermal lens curvature factor |B2| is replaced with approximately 0.026 W / (m·K), the reduction corresponds to a weakened thermal lens. This results in a smaller far-field angle and thus improved beam quality. Specifically, simulations show that when the thermal conductivity k is reduced... KS At approximately 18 W / (m·K), a 5% reduction in the normalized thermal lens curvature factor |B²| can be achieved. Thermal conductivity k KS A 10% reduction can be achieved when the thermal conductivity is approximately 7 W / (m·K). For a 15% reduction, the thermal conductivity should be k. KS ≈2.5W / (m·K).

[0050] Figure 5 The figure shows the effect of aperture thickness d block Simulation of the varying normalized thermal lens curvature factor |B2|. When GaAs(KS) or Al x Ga 1-x When the As(MS,WL) layer is replaced by InGaP (with low thermal conductivity k), the normalized thermal lens curvature factor |B2| decreases, corresponding to the formation of a weakened thermal lens. This results in a smaller far-field angle and thus improves beam quality. In particular, simulations show that when the aperture thickness d... block At approximately 688 nm, a 5% reduction in the normalized thermal lens curvature factor |B2| can be achieved. Aperture thickness d block A 10% reduction can be achieved at approximately 1375nm.

[0051] Figure 6 Simulations of the normalized thermal lens curvature factor |B2| as a function of the lateral distance dx are presented. Here, it is assumed that KS is composed of InGaP. It can be observed that when dx = 0, i.e., when the thermally conductive slit-shaped channel region below the active region is perfectly aligned with the laser strip, the thermal aperture can most effectively reduce the thermal lens curvature factor |B2|.

[0052] Figure 7 It shows that for Figure 4 The structure shown with KS material, with respect to temperature T varying with lateral position (x-axis) and peak temperature T at position x = 0. peak The simulation of the temperature difference ΔT between them. The curve shows the decrease in the curvature of the thermal lens when GaAs is replaced with a material with lower thermal conductivity.

[0053] Figure 8 A schematic diagram of an exemplary second embodiment of a laser diode having two hot holes according to the present invention is shown. The laser diode 10 shown corresponds in principle to, as... Figure 2 The first embodiment of the laser diode 10 with a hot hole 18 according to the present invention is shown. Therefore, the various reference numerals and their corresponding assignments to the various features apply accordingly. However, with... Figure 2In contrast to the illustration in the diagram, the structure with hot holes 18 according to the invention is shown here in both the p-type doped semiconductor material 16 below the active layer 14 and the n-type doped semiconductor material 12 above the active layer 14. A first base 30a is thermally connected to the lower side of the laser diode 10 below the active region 40. Furthermore, a second base 30b is thermally connected to the top of the laser diode 10 above the active region 40. Therefore, cooling can be achieved on both sides of the laser diode 10, thereby effectively suppressing the lateral widening of the heat flow 42 towards the top and bottom of the laser diode 10 through the hot holes 18. Such an embodiment is advantageous when the laser diode 10 is mounted for dual-sided cooling, i.e., when heat dissipation can occur on both sides of the laser diode 10. The laser diode shown is symmetrical with respect to the active layer 14.

[0054] List of reference numerals

[0055] 10 Laser Diodes

[0056] 12 n-type doped semiconductor materials

[0057] 14. Active Layer

[0058] 16 p-type doped semiconductor materials

[0059] 18 hot holes

[0060] 20 Solder layer

[0061] 30 bases

[0062] 30a First base

[0063] 30b Second base

[0064] 40 active areas

[0065] 42 Heat Flow

[0066] dx Lateral distance (slow axis)

[0067] dy (vertical distance, fast axis)

[0068] d block Aperture thickness

[0069] w width

Claims

1. A laser diode (10), the laser diode comprising: An active layer (14) is formed between an n-type doped semiconductor material (12) and a p-type doped semiconductor material (16), wherein the active layer (14) has a width along the longitudinal axis. w The active region (40) is used to generate electromagnetic radiation; In the n-type doped semiconductor material (12) or the p-type doped semiconductor material (16), a material with high thermal conductivity is formed. k block The thermal conductivity is lower than that of the corresponding doped semiconductor materials (12, 16). k bulk The layered thermal holes (18) are used for spatially selective heat transfer from the active region (40) to the side of the corresponding doped semiconductor material (12, 16) opposite to the active layer (14). The laser diode (10) is based on GaAs or Al. x Ga 1-x Furthermore, the hot hole (18) is constructed from an InGaP, InGaAsP, InGaAsSb, or InGaP-InGaAsP superlattice; and The diameter and thickness of the hot hole (18) d block Between 0.3μm and 3μm.

2. The laser diode (10) according to claim 1, wherein, The hot holes (18) are formed by periodically alternating materials.

3. The laser diode (10) according to claim 1, wherein, The hot hole (18) forms a slit-shaped channel region arranged parallel to the active layer (14) for guiding heat flow (42) from the active region (40) toward the outside of the laser diode (10).

4. The laser diode (10) according to claim 3, wherein, The slit-shaped channel region is positioned in the middle relative to the active region (40).

5. The laser diode (10) according to claim 1, wherein, The lateral distance between the outer edge of the active region (40) and the nearest inner edge of the hot hole (18) dx for- w / 6 dx + w / 6.

6. The laser diode (10) according to claim 1, wherein, The vertical distance between the center of the active layer (14) and the top of the hot hole (18) dy 0 μm dy 1 μm.

7. The laser diode (10) according to claim 1, wherein, thermal conductivity k block At most, the corresponding thermal conductivity k bulk 30%.

8. The laser diode (10) according to claim 1, wherein, A layered hot hole (18) is formed in the n-type doped semiconductor material (12), and a layered hot hole (18) is formed in the p-type doped semiconductor material (16).

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