Photonic crystal surface emitting laser

Abstract

The application relates to the technical field of lasers, in particular to a photonic crystal surface-emitting laser, which comprises a chip main body, the chip main body comprising a columnar quantum well array, a pump light absorption layer, a first photonic crystal layer and a second photonic crystal layer, the columnar quantum well array comprising a plurality of columnar quantum wells, the first photonic crystal layer being located on one side surface of the pump light absorption layer in a first direction, the second photonic crystal layer being located on the other side surface of the pump light absorption layer in the first direction, and the two ends of each columnar quantum well in the first direction being in contact with the first photonic crystal layer and the second photonic crystal layer respectively; and a peripheral pumping component, which is annularly arranged at the outer circle of the chip main body and faces the pump light absorption layer. The application is at least beneficial to improving the heat dissipation efficiency, power and light conversion efficiency of the surface-emitting laser.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, and particularly relates to a photonic crystal surface-emitting laser. Background Technology

[0002] High-power light sources such as semiconductor lasers and solid-state lasers play an important role in fields such as biomedicine, aerospace, and lidar. In these lasers, the thermodynamic properties of the distributed Bragg reflection structure (DBR) of the optical resonator greatly limit the improvement of output power and beam quality.

[0003] For example, in compact semiconductor lasers such as vertical-cavity surface-emitting lasers (VCSELs), the core structure of the optical resonator, the Discrete Bragg Array (DBR), is typically composed of dozens of alternating layers of high-refractive-index and low-refractive-index materials. The DBR is used to provide extremely high reflectivity for the laser wavelength, thereby enabling stable oscillation of the laser within the optical resonator. However, the thermal conductivity of traditional DBR materials is generally low. This leads to the continuous accumulation of heat in the active region and within the DBR during the operation of high-power, high-performance lasers, increasing longitudinal thermal resistance and causing severe internal thermal effects. This results in an increase in the laser threshold current, and the output power reaches thermal reversal, leading to laser thermal failure. Summary of the Invention

[0004] In view of this, the present invention aims to provide a photonic crystal surface-emitting laser, which at least helps to improve the heat dissipation efficiency, power and optical conversion efficiency of the surface-emitting laser.

[0005] To achieve the above objectives, the technical solution created by this invention is implemented as follows: This invention provides a photonic crystal surface-emitting laser, comprising: a chip body, the chip body including: a columnar quantum well array, a pump light absorption layer, a first photonic crystal layer, and a second photonic crystal layer; the columnar quantum well array includes multiple columnar quantum wells, which are spaced apart and extend along a first direction, and are arranged in an array along the extension direction of a plane perpendicular to the first direction; the pump light absorption layer covers the columnar quantum well array and fills the gaps between different columnar quantum wells; one side surface of the pump light absorption layer in the first direction exposes the first end of each columnar quantum well, and the other side surface of the pump light absorption layer in the first direction exposes the second end of each columnar quantum well; the first photonic crystal layer is located on one side surface of the pump light absorption layer in the first direction, and the second photonic crystal layer is located on the other side surface of the pump light absorption layer in the first direction; the two ends of each columnar quantum well in the first direction are in contact with the first photonic crystal layer and the second photonic crystal layer, respectively; and a peripheral pump assembly, which is arranged around the outer ring of the chip body and faces the pump light absorption layer.

[0006] Furthermore, the pump light absorption layer has an optical thin film on the side facing the peripheral pump component. The side of the optical thin film facing the peripheral pump component has a transmittance of more than 95% for pump light, and the side of the optical thin film facing the pump light absorption layer has a reflectance of more than 99% for the target wavelength laser.

[0007] Furthermore, the first photonic crystal layer includes a first material body and a plurality of first holes disposed within the first material body, the plurality of first holes being arranged in an array, and each first hole penetrating the first material body along a first direction; the second photonic crystal layer includes a second material body and a plurality of second holes disposed within the second material body, the plurality of second holes being arranged in an array, and each second hole penetrating the second material body along a direction perpendicular to the first direction.

[0008] Furthermore, the thermal conductivity of both the first and second material bulks is greater than 400 W / (m²). K).

[0009] Furthermore, the first material body comprises diamond or silicon carbide, and the second material body comprises diamond or silicon carbide.

[0010] Furthermore, in the first direction, the thickness of the first photonic crystal layer is the same as the thickness of the second photonic crystal layer.

[0011] Furthermore, in the first direction, the thickness of the first photonic crystal layer is in the range of 1.4 μm to 1.6 μm, and the thickness of the second photonic crystal layer is in the range of 1.4 μm to 1.6 μm.

[0012] Furthermore, the pump light absorption layer has an absorption coefficient for pump light greater than 1.5 × 10⁻⁶. 4 cm -1 The pump light absorption layer is made of GaAs; the thickness of the pump light absorption layer is in the range of 1.8 μm to 2.2 μm.

[0013] Furthermore, the columnar quantum wells are cylindrical; the diameter of the columnar quantum wells is in the range of 0.8 μm to 1.2 μm; and the intercolumn gaps between multiple columnar quantum wells are in the range of 1.3 μm to 1.7 μm.

[0014] Furthermore, the peripheral pumping assembly includes multiple pumping units, which are arranged at intervals along a ring direction. Each pumping unit emits pump light, which is coupled into the pump light absorption layer.

[0015] Compared with existing technologies, the present invention achieves the following beneficial effects: Photonic crystals, due to their photonic bandgap effect, can achieve high light reflection with extremely thin thickness. Using materials with high thermal conductivity to fabricate photonic crystals ensures efficient heat dissipation while achieving high reflectivity. Therefore, the photonic crystal surface-emitting laser provided by this invention uses a photonic crystal layer (first photonic crystal layer and second photonic crystal layer) instead of the DBR at both ends of the traditional laser resonant cavity, which is beneficial to improving the heat dissipation efficiency of the laser and solving the problem of performance degradation caused by thermal effects under high power density. The active region of this invention uses a columnar quantum well array, which can ensure that the quantum wells are injected with charge carriers in a large area, efficiently, and uniformly, thereby significantly improving the optical conversion efficiency. The peripheral pumping component performs side pumping on the chip body through optical coupling, which is beneficial to improving pumping efficiency. Through the synergistic design of a high thermal conductivity photonic crystal layer replacing the traditional DBR, a columnar quantum array active region, an optical thin film deposited on the outside of the pump light absorption layer, and peripheral pumping components, this invention achieves a surface-emitting laser with high heat dissipation efficiency, high optical conversion efficiency, high beam quality, and high integration. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the structure of the photonic crystal surface-emitting laser described in the embodiment of the present invention; Figure 2 A top view of the photonic crystal surface-emitting laser described in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 100, chip body; 106, pump light absorption layer; 104, first photonic crystal layer; 107, second photonic crystal layer; 105, columnar quantum well; X, first direction; 103, output laser; 102, pump light. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] refer to Figure 1 and Figure 2This invention provides a photonic crystal surface-emitting laser, comprising: a chip body 100, the chip body 100 including: a columnar quantum well array, a pump light absorption layer 106, a first photonic crystal layer 104, and a second photonic crystal layer 107; the columnar quantum well array including a plurality of columnar quantum wells 105, each columnar quantum well 105 being spaced apart and extending along a first direction X; the plurality of columnar quantum wells 105 being arranged in an array along the extension direction of a plane perpendicular to the first direction X; the pump light absorption layer 106 covering the columnar quantum well array and filling the gaps between the different columnar quantum wells 105; one side surface of the pump light absorption layer 106 in the first direction X is exposed. The first end of each columnar quantum well 105 is exposed, and the second end of each columnar quantum well 105 is exposed on the other side surface of the pump light absorption layer 106 in the first direction X. The first photonic crystal layer 104 is located on one side surface of the pump light absorption layer 106 in the first direction X, and the second photonic crystal layer 107 is located on the other side surface of the pump light absorption layer 106 in the first direction X. The two ends of each columnar quantum well 105 in the first direction X are in contact with the first photonic crystal layer 104 and the second photonic crystal layer 107, respectively. The peripheral pump assembly is arranged around the outer ring of the chip body 100 and faces the pump light absorption layer 106.

[0024] The first photonic crystal layer 104 is a highly thermally conductive periodic micro / nano structure with a photonic bandgap effect. The first photonic crystal layer 104 is designed to partially reflect the target wavelength laser. The first photonic crystal layer 104 and the second photonic crystal layer 107 together constitute the two reflecting ends of the optical resonant cavity, so that the target wavelength laser generated by the columnar quantum well array oscillates in the optical resonant cavity and repeatedly passes through the active region formed by the columnar quantum well array to obtain a sufficiently high gain. At the same time, since the first photonic crystal layer 104 uses a high thermal conductivity material, it also constitutes the top heat dissipation channel of the chip body 100, and together with the second photonic crystal layer 107, it forms a vertical heat dissipation structure with efficient heat conduction on both sides.

[0025] The second photonic crystal layer 107 is also a periodic micro / nano structure with photonic bandgap effect, made of a high thermal conductivity material. Specifically, it can be a photonic crystal structure formed by etching periodic holes in a high thermal conductivity material. By designing the period and duty cycle of the photonic crystal, high reflectivity for the target wavelength laser can be achieved. At the same time, the second photonic crystal layer 107 also serves as the bottom heat dissipation structure of the chip body 100.

[0026] This invention utilizes a photonic crystal layer to replace the traditional DBR, which not only significantly reduces the optical path loss inside the chip and avoids unnecessary waste heat generated in the mirror, but also, thanks to the high thermal conductivity of the high thermal conductivity material, helps to effectively suppress the thermal effect of the device.

[0027] In addition, in terms of heat dissipation, each columnar quantum well 105 generates heat independently. The heat is directly conducted in the columnar quantum well 105 along the first direction X to the first photonic crystal layer 104 and the second photonic crystal layer 107. In some embodiments, the second photonic crystal layer 107 can be in contact with the SiC heat sink, and the first photonic crystal layer 104 can be dissipated by air convection or additional heat dissipation structures to form a double-sided vertical high-efficiency heat dissipation channel.

[0028] It should be emphasized that the thickness of the first photonic crystal layer 104 and the second photonic crystal layer 107 are thinner than those of traditional DBR. Combined with high thermal conductivity, this can greatly reduce the interfacial thermal resistance, allowing the heat inside the chip body 100 to be quickly dissipated, effectively suppressing thermal effects, avoiding wavelength drift and thermal failure, and enabling the laser to operate stably and continuously at high power density.

[0029] Furthermore, the pump light absorption layer 106 has an optical thin film on the side facing the peripheral pump component. The transmittance of the optical thin film facing the peripheral pump component to the pump light 102 is greater than 95%, and the reflectivity of the optical thin film facing the pump light absorption layer 106 to the target wavelength laser is greater than 99%. In this way, it can be ensured that the pump light 102 enters the pump light absorption layer 106 efficiently and with low loss, while reflecting the light escaping from the side of the columnar quantum well 105 back into the optical resonant cavity, which helps to reduce lateral optical loss and improve light extraction efficiency.

[0030] In some embodiments, the reflectivity of the first photonic crystal layer 104 is >98%, and the reflectivity of the second photonic crystal layer 107 is >99.99%.

[0031] Furthermore, the first photonic crystal layer 104 includes a first material body and a plurality of first holes disposed within the first material body, the plurality of first holes being arranged in an array, and each first hole penetrating the first material body along a first direction X; the second photonic crystal layer 107 includes a second material body and a plurality of second holes disposed within the second material body, the plurality of second holes being arranged in an array, and each second hole penetrating the second material body along the same direction perpendicular to the first direction X.

[0032] The first hole and the second hole can be cylindrical or other irregular shapes.

[0033] Furthermore, the thermal conductivity of both the first and second material bulks is greater than 400 W / (m²). K).

[0034] Furthermore, the primary material of the first material includes diamond, silicon carbide, or other materials with high thermal conductivity, and the primary material of the second material also includes diamond, silicon carbide, or other materials with high thermal conductivity. Diamond has a thermal conductivity of 1000 W / (m²). K)~2000W / (m Within the range of K), the thermal conductivity of silicon carbide is 400 W / (m²). K)~500W / (m Within the range of K).

[0035] Furthermore, in the first direction X, the thickness of the first photonic crystal layer 104 is the same as the thickness of the second photonic crystal layer 107.

[0036] Furthermore, in the first direction X, the thickness of the first photonic crystal layer 104 is in the range of 1.4 μm to 1.6 μm, and the thickness of the second photonic crystal layer 107 is in the range of 1.4 μm to 1.6 μm.

[0037] In some embodiments, both the first hole and the second hole are cylindrical holes. The duty cycle of the plurality of first holes arranged in an array in the first material body is in the range of 50% to 65%, and the duty cycle of the plurality of second holes arranged in an array in the second material body is in the range of 50% to 65%. The diameter of the first hole is in the range of 190 nm to 230 nm, the diameter of the second hole is in the range of 190 nm to 230 nm, the lattice constant of the first photonic crystal layer 104 is in the range of 340 nm to 370 nm, and the lattice constant of the second photonic crystal layer 107 is in the range of 340 nm to 370 nm.

[0038] Furthermore, the absorption coefficient of the pump light absorption layer 106 for the pump light 102 is greater than 1.5 × 10⁻⁶. 4 cm -1 The material of the pump light absorption layer 106 includes GaAs; in the first direction X, the thickness of the pump light absorption layer 106 is in the range of 1.8 μm to 2.2 μm.

[0039] It should be noted that light emission from the surface of the columnar quantum well 105 can be achieved by controlling the cross-sectional area (or diameter), length, and arrangement period of the columnar quantum well 105, so that the injected carrier density is highly matched with the optical field distribution, reducing nonradiative recombination losses and improving internal quantum effects. The active region formed by the columnar quantum well array and the photonic crystal layer have a band-edge resonance effect, which can select specific oscillation modes, suppress higher-order modes, improve beam quality, and enhance the local optical field density at the resonance wavelength, thereby increasing the stimulated emission probability and improving the optical conversion efficiency.

[0040] Furthermore, the columnar quantum well 105 is cylindrical; the diameter of the columnar quantum well 105 is in the range of 0.8 μm to 1.2 μm; and the inter-column gap of the multiple columnar quantum wells 105 is in the range of 1.3 μm to 1.7 μm.

[0041] In some embodiments, each columnar quantum well 105 includes a quantum well layer and a barrier layer that are alternately and periodically arranged along a first direction.

[0042] Furthermore, the peripheral pumping assembly includes multiple pumping units 101, which are arranged at intervals along a ring direction. Each pumping unit 101 emits pump light 102, which is coupled into the pump light absorption layer 106 to achieve optical pumping.

[0043] In some embodiments, the pump unit 101 may be an edge-emitting laser or a diode laser.

[0044] It should be noted that the pump light band matches the absorption peak of the pump light absorption layer 106, and the pump light absorption layer 106 is pumped uniformly over a large area directly from the side, which is beneficial to effectively improve the light absorption efficiency and carrier injection efficiency.

[0045] In some embodiments, the peripheral pump assembly can be bonded to the same plane as the chip body 100. In some examples, both the peripheral pump assembly and the chip body 100 are disposed on the SiC heat sink. For the SiC heat sink, a miniature thermoelectric cooler can be used for precise temperature control, which is beneficial to further improve the working stability of the laser.

[0046] In some embodiments, the peripheral pumping component can be composed of an array of four side-emitting lasers, each corresponding to one of the four sides of the chip body 100. Each side-emitting laser is an InGaAs / AlGaAs strained quantum well side-emitting laser diode with an emission wavelength of 808nm and a single-tube output power of 1W. Each side-emitting laser can include multiple light-emitting units, and the number of light-emitting units in each side-emitting laser needs to match the side dimensions of the chip body 100. If each side of the chip body 100 is 2mm long, then each side-emitting laser can contain 10 light-emitting units. The second photonic crystal layer 107 is made of single-crystal diamond material, and a periodic cylindrical hole array is formed by electron beam lithography and inductively coupled plasma etching processes. The structure has a lattice constant of 350 nm, a cylindrical aperture diameter of 200 nm, an etching depth of 1.5 μm that penetrates the second photonic crystal layer 107, and a duty cycle of approximately 57%. This structure exhibits a reflectivity >99.99% for a target wavelength laser of 950 nm, a reflection band width of approximately 100 nm, and a total thickness of approximately 1.5 μm for the second photonic crystal layer 107. A 10 nm thick silicon oxide or aluminum oxide layer can be used as a bonding or insulating layer between the second photonic crystal layer 107 and the pump light absorption layer 106. An ordered array of columnar quantum wells is embedded within the pump light absorption layer 106 to form the central luminescent region. The pump light absorption layer 106 is made of GaAs and has a thickness of 2 μm. The absorption coefficient of the pump light absorption layer 106 for the 808 nm pump light 102 is greater than 1.5 × 10⁻⁶. 4 cm -1The pump light absorption layer 106 has optical thin films deposited on all four outer surfaces. The outer surface of the optical thin film has a transmittance of >95% for the 808nm pump light 102 (achieved through the deposition of MgF2 / SiO2), while the inner surface of the optical thin film has a reflectance of >99% for the 950nm target wavelength laser (achieved through the deposition of Ta2O5 / SiO2). The columnar quantum well 105 is an InGaAs / GaAs strain-compensated quantum well structure with a well width of 8nm and a barrier width of 12nm. The number of wells can be three; the columnar quantum wells 105 have a diameter of 1 μm and a height of 2 μm (consistent with the thickness of the pump light absorption layer 106), with an arrangement period of 2.5 μm (a column spacing of 1.5 μm), and can form a square array or a hexagonal array; the columnar quantum wells 105 can be formed by epitaxially growing a bulk quantum well structure using MOCVD (metal-organic chemical vapor deposition), followed by electron beam lithography and dry etching to form a columnar quantum well array. The sides of the columnar quantum wells 105 can be... Sidewall passivation is achieved by forming a passivation layer; the first photonic crystal layer 104 also uses single-crystal diamond material with a lattice constant of 360 nm, a cylindrical hole diameter of 220 nm, an etching depth of 1.5 μm, and a duty cycle of approximately 61%. This structure has a reflectivity of 98.5% and a transmittance of 1.5% for a target wavelength laser of 950 nm, and is used for laser output. The thickness of the first photonic crystal layer 104 is approximately 1.5 μm, and a 50 nm thick layer of silicon nitride or aluminum oxide can be deposited on top of it. The window layer is used to prevent surface oxidation and carrier recombination. The chip body 100 and the four peripheral edge-emitting lasers are flip-chip bonded to a high thermal conductivity SiC heat sink (thermal conductivity of about 400 W / (m·K)). AuSn eutectic solder can be used. The entire module is packaged in ceramic or metal. A light-transmitting window (such as a glass window with an anti-reflection coating) is left at the top for outputting 950nm laser. A micro thermoelectric cooler can be attached below the SiC heat sink to achieve precise temperature control.

[0047] The specific working principle of the photonic crystal surface-emitting laser provided in the above embodiment is as follows: During operation, a current is applied to the laser of the peripheral pumping component, causing it to emit pump light 102. The pump light 102 enters the pump light absorption layer 106 from the side of the chip body 100 through the optical thin film. After entering the pump light absorption layer 106, the pump light 102 undergoes multiple scattering, refraction, and reflection within the pump light absorption layer 106. Due to the continuous injection of pump light 102 from the side, and the combined effect of the high transmission of the incident pump light 102 by the optical thin film and the high reflection of the target wavelength laser, the effective optical path of the pump light 102 within the pump light absorption layer 106 is significantly increased. The absorption efficiency can exceed 90%. After the pump light 102 is absorbed by the pump light absorption layer 106, a large number of electron-hole pairs are generated. These charge carriers diffuse rapidly and are captured by the columnar quantum wells 105 embedded in the pump light absorption layer 106. The charge carriers in the columnar quantum wells 105 recombine and radiate, generating laser light of the target wavelength. The target wavelength laser light and the unconverted pump light 102 oscillate repeatedly between the second photonic crystal layer 107 and the first photonic crystal layer 104. Each time it passes through the columnar quantum well array, it gains gain. When the gain exceeds the loss, the target wavelength laser light is vertically output from the surface of the first photonic crystal layer 104. The beam quality factor M of the output laser light 103 is... 2 With a beam angle of <1.5 and a divergence angle of <5°, high beam quality surface emission output is achieved.

[0048] The above embodiments provide a photonic crystal surface-emitting laser with high heat dissipation efficiency, high power, and high efficiency. Traditional high-power lasers (such as VECSELs and solid-state lasers) generally use distributed Bragg mirrors (DBRs) as resonant cavity reflecting elements. However, DBRs have problems such as low thermal conductivity, thick structure, and large interface thermal resistance, which seriously limit the heat dissipation performance and output stability of lasers at high power densities. This invention uses high thermal conductivity materials (such as diamond and silicon carbide) to prepare photonic crystal layers to replace traditional DBRs. It utilizes the photonic bandgap effect to achieve high reflectivity with an extremely thin structure thickness. At the same time, it achieves efficient heat dissipation by virtue of the high thermal conductivity of the high thermal conductivity materials. In addition, a columnar quantum well array is embedded in the pump light absorption layer 106, and together with the peripheral pump components and the side optical thin film of the pump light absorption layer 106, high pump light absorption efficiency, high light conversion efficiency, high beam quality, and high integration are achieved.

[0049] In the photonic crystal surface-emitting laser provided by this invention, a columnar quantum well array is embedded within a pump light absorption layer 106. The columnar quantum wells 105 have a lower energy band, while the surrounding pump light absorption layer 106 has a higher energy band. An energy band depression is formed between the pump light absorption layer 106 and the columnar quantum wells 105, causing photogenerated carriers generated by the pump light absorption layer 106 to converge into the columnar quantum wells 105 in the lower barrier layer, achieving high pump light absorption efficiency. Furthermore, in this structure, each columnar quantum well 105 generates heat independently, and the heat can be directly conducted along the column to the photonic crystal layer, forming a vertical, efficient heat dissipation channel penetrating the chip body 100, effectively suppressing chip thermal effects and avoiding wavelength drift. Mitigating thermal damage within the chip enables the laser to operate stably at high power densities. The use of a columnar quantum well array offers significant advantages in carrier injection compared to traditional planar layered quantum well structures. Planar layered quantum wells employ a top-down vertical injection method, where carriers sequentially pass through multiple well layers. During this process, carriers are consumed layer by layer, leading to insufficient injection in lower layers and uneven gain across quantum well layers, resulting in decreased optical conversion efficiency. In contrast, the columnar quantum well 105 injects carriers from all sides of the column, with a short and uniform injection path. This allows for flexible and efficient simultaneous injection of carriers into multiple quantum wells, ensuring sufficient gain for each well and significantly improving internal quantum efficiency.

[0050] This invention uses a high thermal conductivity photonic crystal layer to replace the traditional DBR structure. It utilizes the photonic bandgap effect to achieve high reflectivity with an extremely thin structure thickness, fundamentally solving the huge interfacial thermal resistance caused by the excessively thick traditional DBR. The extremely thin reflective layer structure enables real-time and efficient heat dissipation. The high thermal conductivity photonic crystal layer can efficiently dissipate heat from the gain medium, reduce its temperature, and alleviate gain attenuation and nonradiative recombination at high temperatures, thereby improving the optical conversion efficiency of the laser.

[0051] The columnar quantum well 105 forms a band-edge resonance effect with the photonic crystal layer, which significantly enhances the local optical field density at the resonance wavelength and increases the stimulated emission probability. By designing the cross-sectional area, arrangement period of the columnar quantum well 105 and the band gap and band-edge characteristics of the photonic crystal layer, precise filtering of intrinsic cavity modes can be achieved, which effectively suppresses higher-order modes, stabilizes the fundamental mode or low-order modes, and improves the internal quantum efficiency and the absorption efficiency of the pump light 102.

[0052] The peripheral pumping component adopts a multi-angle lateral pumping method. The pump light 102 enters the pump light absorption layer 106 from the side through the optical thin film with a large area and high uniformity. The pump light absorption layer 106 has a high absorption coefficient for the pump light 102, and the optical thin film enables the pump light 102 to enter efficiently and reduces reflection loss. The pump light 102 undergoes multiple scattering, refraction and reflection in the pump light absorption layer 106, which greatly increases the effective optical path. In addition, the high reflectivity of the optical thin film for the target wavelength laser purifies the output spectrum and laser mode while preventing the unabsorbed energy carried by the pump light 102 from escaping from the side, further improving the utilization efficiency of the pump light 102.

[0053] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0054] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A photonic crystal surface-emitting laser, characterized in that, include: The chip body includes: a columnar quantum well array, a pump light absorption layer, a first photonic crystal layer, and a second photonic crystal layer. The columnar quantum well array includes multiple columnar quantum wells, which are spaced apart and extend along a first direction. The multiple columnar quantum wells are arranged in an array along the extension direction of a plane perpendicular to the first direction. The pump light absorption layer covers the columnar quantum well array and fills the gaps between different columnar quantum wells. The pump light absorption layer exposes the first end of each columnar quantum well on one side surface in the first direction, and exposes the second end of each columnar quantum well on the other side surface in the first direction. The first photonic crystal layer is located on one side surface of the pump light absorption layer in the first direction, and the second photonic crystal layer is located on the other side surface of the pump light absorption layer in the first direction. The two ends of each columnar quantum well in the first direction are in contact with the first photonic crystal layer and the second photonic crystal layer, respectively. A peripheral pumping assembly is disposed around the outer ring of the chip body and faces the pump light absorption layer.

2. The photonic crystal surface-emitting laser according to claim 1, characterized in that, The pump light absorption layer has an optical thin film on the side facing the peripheral pump component. The side of the optical thin film facing the peripheral pump component has a transmittance of pump light greater than 95%, and the side of the optical thin film facing the pump light absorption layer has a reflectance of target wavelength laser greater than 99%.

3. The photonic crystal surface-emitting laser according to claim 1, characterized in that, The first photonic crystal layer includes a first material body and a plurality of first holes disposed in the first material body, the plurality of first holes being arranged in an array, and each first hole penetrating the first material body along the first direction; The second photonic crystal layer includes a second material body and a plurality of second holes disposed within the second material body. The plurality of second holes are arranged in an array, and each second hole penetrates the second material body in a direction perpendicular to the first direction.

4. The photonic crystal surface-emitting laser according to claim 3, characterized in that, The thermal conductivity of both the first and second material bulks is greater than 400 W / (m²). K).

5. The photonic crystal surface-emitting laser according to claim 4, characterized in that, The first material body is made of diamond or silicon carbide, and the second material body is made of diamond or silicon carbide.

6. The photonic crystal surface-emitting laser according to claim 3, characterized in that, In the first direction, the thickness of the first photonic crystal layer is the same as the thickness of the second photonic crystal layer.

7. The photonic crystal surface-emitting laser according to claim 6, characterized in that, In the first direction, the thickness of the first photonic crystal layer is in the range of 1.4 μm to 1.6 μm, and the thickness of the second photonic crystal layer is in the range of 1.4 μm to 1.6 μm.

8. The photonic crystal surface-emitting laser according to claim 1, characterized in that, The pump light absorption layer has an absorption coefficient for pump light greater than 1.5 × 10⁻⁶. 4 cm -1 The material of the pump light absorption layer includes GaAs; the thickness of the pump light absorption layer is in the range of 1.8 μm to 2.2 μm.

9. The photonic crystal surface-emitting laser according to claim 1, characterized in that, The columnar quantum well is cylindrical; the diameter of the columnar quantum well is in the range of 0.8 μm to 1.2 μm; the intercolumn gap of multiple columnar quantum wells is in the range of 1.3 μm to 1.7 μm.

10. The photonic crystal surface-emitting laser according to claim 1, characterized in that, The peripheral pumping assembly includes multiple pumping units, which are arranged at intervals along a ring direction. Each pumping unit emits pump light, which is coupled into the pump light absorption layer.

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