Photonic crystal surface-emitting laser device and optical system

Abstract

The application provides a photonic crystal surface emitting laser device, comprising a light emitting module and a driving module. The light emitting module comprises a photonic crystal layer, an active light emitting layer on one side of the photonic crystal layer, a first electrode on the side of the active light emitting layer away from the photonic crystal layer, and a second electrode at least partially on the side of the active light emitting layer away from the photonic crystal layer. The driving module is electrically connected to the surfaces of the first electrode and the second electrode away from the photonic crystal layer, and is used for outputting driving signals to the first electrode and the second electrode to drive the active light emitting layer to generate photons, and the photons are subjected to Bragg diffraction oscillation after being incident on the photonic crystal layer to generate laser. The application also provides an optical system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical detection technology, and in particular to a photonic crystal surface-emitting laser device and an optical system using the same. BACKGROUND

[0002] A photonic crystal surface-emitting laser (PCSEL) has excellent beam quality, small size, low energy consumption, easy integration, high reliability, and can be widely used in three-dimensional sensing systems, consumer electronics, automotive lidar, smart devices, medical health devices, and other optical systems.

[0003] The existing PCSEL main structure includes a epitaxial substrate with a thickness of at least 100 microns to maintain mechanical strength to avoid wafer breakage in the PCSEL. When a high current is injected, the active light-emitting layer in the PCSEL will generate a large amount of heat during electroluminescence. This heat is transferred through the epitaxial substrate and the packaging material of the PCSEL. However, the epitaxial substrate makes the heat dissipation path longer and the heat dissipation efficiency lower, and the PCSEL light output power cannot be improved and the service life is shortened. The existing PCSEL has a light-emitting area, and an electrode wiring area needs to be reserved around the light-emitting area. The electrode wire bonding area is several times the area of the light-emitting area, causing the epitaxial substrate area to be wasted and increasing the cost of the packaging material. The electrode wire bonding area is also prone to parasitic capacitance and parasitic inductance, which reduces the response speed of the PCSEL and is not conducive to high-frequency operation of the PCSEL. In the existing PCSEL, due to the different diffusion speeds of the current in each direction, the current density injected into the active light-emitting layer is prone to be uneven.

[0004] Therefore, the existing PCSEL needs to be improved. SUMMARY

[0005] The first aspect of the present application provides a photonic crystal surface-emitting laser device, comprising:

[0006] A light-emitting module, comprising:

[0007] A photonic crystal layer;

[0008] An active light-emitting layer located on one side of the photonic crystal layer;

[0009] A first electrode located on a side of the active light-emitting layer away from the photonic crystal layer; and

[0010] A second electrode at least partially located on a side of the active light-emitting layer away from the photonic crystal layer; and

[0011] A driving module electrically contacts the first electrode and the second electrode respectively and outputs a driving signal to the first electrode and the second electrode to drive the active light-emitting layer to generate photons, which are incident on the photonic crystal layer to generate laser.

[0012] The second aspect of the present application provides an optical system, comprising:

[0013] The photonic crystal surface-emitting laser device as described above; and

[0014] A control device electrically connected to the photonic crystal surface-emitting laser device and outputs the driving signal to the photonic crystal surface-emitting laser device to drive the photonic crystal surface-emitting laser device to emit laser.

[0015] The photonic crystal surface-emitting laser device integrates the driving module and the light-emitting module, which is beneficial to improve the switching speed of the photonic crystal surface-emitting laser. The light-emitting module generates heat during operation. Since the light-emitting module does not include a substrate in the embodiment, that is, the first electrode and the second electrode of the light-emitting module are directly combined with the driving module without the substrate spacing, which is beneficial to heat dissipation of the light-emitting module, and thus is beneficial to improve the light-emitting power and the service life of the photonic crystal surface-emitting laser. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of the module structure of the optical system in the embodiment of the present application.

[0017] Figure 2 The figure is a schematic diagram of the planar structure of the light-emitting module in the embodiment of the present application. Figure 1

[0018] The figure is a schematic diagram of the cross-sectional structure of the light-emitting module along the line Ⅲ-Ⅲ in the embodiment of the present application. Figure 3 Figure 2 The figure is a schematic diagram of the cross-sectional structure of the light-emitting module along the line Ⅳ-Ⅳ in the embodiment of the present application.

[0019] Figure 4 Figure 2 The figure is a schematic diagram of the cross-sectional structure of the light-emitting module along the line Ⅳ-Ⅳ in the embodiment of the present application.

[0020] Figure 5 The figure is a schematic diagram of the planar structure of the photonic crystal surface-emitting laser in other embodiments of the present application.

[0021] Figure 6 The figure is a schematic diagram of the planar structure of the driving module in the embodiment of the present application. Figure 1

[0022] The figure is a schematic diagram of the planar structure of the light-emitting module and the driving module in the embodiment of the present application. Figure 7 Figure 6 The figure is a schematic diagram of the cross-sectional structure of the light-emitting module and the driving module along the line Ⅶ-Ⅶ in the embodiment of the present application.

[0023] ​​​Figure 8 Fig. 6 is a graph showing the operating temperature of the photonic crystal surface-emitting laser of the first example embodiment of the present application as a function of driving current at different ambient temperatures.

[0024] Figure 9 Fig. 9 is a graph showing the operating temperature of the photonic crystal surface-emitting laser of the first comparative example as a function of driving current at different ambient temperatures.

[0025] Figure 10 Fig. 10 is a graph showing the operating temperature of the photonic crystal surface-emitting laser of the second comparative example as a function of driving current at different ambient temperatures.

[0026] Figure 11 Fig. 11 is a graph showing the operating temperature of the photonic crystal surface-emitting laser of the third comparative example as a function of driving current at different ambient temperatures.

[0027] Explanation of main component symbols

[0028] Optical system 100

[0029] Photonic crystal surface-emitting laser device 10

[0030] Light-emitting module 2

[0031] Insulating layer 20

[0032] Photonic crystal layer 21

[0033] Ohmic contact layer 211

[0034] Second cladding layer 212

[0035] Vias 213

[0036] Active light-emitting layer 22

[0037] Quantum well active light-emitting layer 221

[0038] Barrier layer 222

[0039] First cladding layer 23

[0040] Bragg reflector 24

[0041] First refractive layer 241

[0042] Second refractive layer 242

[0043] Transparent conductive layer 25

[0044] Light-transmitting substrate 26

[0045] Thermally conductive adhesive layer 27

[0046] First electrode 28

[0047] Third conductive portion 281

[0048] Fourth conductive portion 282

[0049] Extension portion 283

[0050] Second electrode 29

[0051] First conductive portion 291

[0052] Second conductive portion 292

[0053] Inner wall 2921

[0054] Driving module 3

[0055] Substrate 31

[0056] Gate G

[0057] Source S

[0058] Drain D

[0059] Connection electrode P

[0060] Buffer layer 32

[0061] Channel layer 33

[0062] P-type gallium nitride layer 331

[0063] Aluminum gallium nitride barrier layer 332

[0064] Undoped gallium nitride channel 333

[0065] Electrode layer 34

[0066] Insulating material layer 35

[0067] Notch S0

[0068] Accommodation space S1

[0069] Hollow space S2

[0070] Curves X, Y, Z, X1, X2, X3, X4, Y1, Y2, Y3, Y4, Z1, Z2, Z3, Z4

[0071] The following detailed description will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0072] Please refer to Figure 1The optical system 100 of the present application comprises a photonic crystal surface emitting laser device 10. The optical system 100 can be a face recognition sensing device, a laser radar, etc., which can be applied to various consumer electronic devices such as smart phones, augmented reality (AR) glasses, virtual reality (VR) glasses, etc., and can also be applied to cars, home or medical equipment, and to smart factories, automated warehouses, unmanned vehicles, etc.

[0073] The optical system 100 further comprises a control device (not shown in the figure) electrically connected to the photonic crystal surface emitting laser device 10. When the photonic crystal surface emitting laser device 10 is applied to the various optical systems 100 described above, it is used to emit laser light according to the driving signal output by the control device, so that the optical system 100 realizes the functions of interactive display, security recognition, indoor environment sensing or close-range sensing, etc. In the present embodiment, the control device can be a wafer, a wafer set, a control mainboard, etc.

[0074] The photonic crystal surface emitting laser device 10 comprises a light emitting module 2 and a driving module 3 electrically connected to each other. The driving module 3 is used to apply a driving signal (driving voltage or driving current) to the light emitting module 2, and the light emitting module 2 is used to emit laser light according to the driving signal (driving voltage or driving current).

[0075] Please refer to Figure 2 and Figure 3 In the present embodiment, the light emitting module 2 comprises a photonic crystal layer 21, an active light emitting layer 22, a first cladding layer 23 and a Bragg reflector 24 stacked in sequence.

[0076] The photonic crystal layer 21 comprises an ohmic contact layer 211 and a second cladding layer 212 stacked together, and the second cladding layer 212 is located between the ohmic contact layer 211 and the active light emitting layer 22. In the present embodiment, the material of the ohmic contact layer 211 is P-type gallium arsenide, and the second cladding layer 212 is P-type aluminum gallium arsenide. In other embodiments, the material of the ohmic contact layer 211 can also be indium phosphide or arsenic indium gallium phosphide. A plurality of through holes 213 are formed in the photonic crystal layer 21 and arranged at intervals. Each through hole 213 penetrates the ohmic contact layer 211 and the second cladding layer 212.

[0077] The active light-emitting layer 22 includes a plurality of quantum well active light-emitting layers 221 and a plurality of barrier layers 222. The plurality of quantum well active light-emitting layers 221 and the plurality of barrier layers 222 are alternately stacked. That is, the quantum well active light-emitting layers 221 and the barrier layers 222 are alternately arranged. In the present embodiment, the active light-emitting layer 22 includes three quantum well active light-emitting layers 221 and four barrier layers 222 which are alternately stacked. The material of each quantum well active light-emitting layer 221 is indium gallium arsenide, and the material of each barrier layer 222 is gallium arsenide, for emitting laser with a wavelength of 905 nm to 1550 nm (including the end values). In other embodiments, the quantum well active light-emitting layers 221 can also be aluminum gallium indium arsenide or indium gallium arsenide phosphide, and the barrier layers 222 can also be aluminum gallium arsenide or aluminum gallium indium arsenide.

[0078] The active light-emitting layer 22 is used to generate photons under the driving of the driving signal. The photons generated by the active light-emitting layer 22 propagate in all directions, and the photons propagating into the photonic crystal layer 21 repeatedly oscillate in the photonic crystal layer 21 until the light-emitting module 2 reaches a gain and loss balance state, and laser is generated.

[0079] The material of the first cladding layer 23 can be N-type aluminum gallium arsenide. The first cladding layer 23 and the second cladding layer 212 are used to cooperate to lock the photons emitted by the active light-emitting layer 22 and reduce the propagation of the photons toward the Bragg reflector 24. In the present embodiment, the material of the first cladding layer 23 is aluminum gallium arsenide. In other embodiments, the materials of the first cladding layer 23 and the second cladding layer 212 can also be aluminum indium arsenide, indium phosphide, or gallium arsenide phosphide.

[0080] The Bragg reflector 24 includes a plurality of first refractive layers 241 and a plurality of second refractive layers 242. The plurality of first refractive layers 241 and the plurality of second refractive layers 242 are alternately stacked. Each first refractive layer 241 has the same refractive index, each second refractive layer 242 has the same refractive index, and the refractive index of the first refractive layer 241 is different from the refractive index of the second refractive layer 242. The Bragg reflector 24 is used to reflect the received photons toward the photonic crystal layer 21, so as to recycle the photons escaping from the first cladding layer 23, thereby reducing light loss and improving the light-emitting power of the photonic crystal surface-emitting laser device 10. In the present embodiment, the Bragg reflector 24 includes three first refractive layers 241 and three second refractive layers 242, which are alternately arranged.

[0081] Please continue to refer to Figure 2 and Figure 3 In the present embodiment, the light-emitting module 2 further includes a transparent conductive layer 25, a light-transmitting substrate 26, and a heat-conducting adhesive layer 27.

[0082] The heat-conducting glue layer 27 is located between the transparent conductive layer 25 and the light-transmitting substrate 26, and is used to adhere and fix the transparent conductive layer 25 and the light-transmitting substrate 26, and to conduct heat generated during the operation of the light-emitting module 2. The transparent conductive layer 25 is located on one side of the photonic crystal layer 21 away from the Bragg reflector 24 and fills the plurality of periodically distributed through holes 213 in the photonic crystal layer 21. The light-transmitting substrate 26 is located on one side of the transparent conductive layer 25 away from the Bragg reflector 24.

[0083] In this embodiment, the transparent conductive layer 25 is made of indium tin oxide (ITO). The light-transmitting substrate 26 can be made of a light-transmitting material such as sapphire (Sapphire), gallium arsenide (GaAs), gallium nitride (GaN), silicon (Si), silicon carbide (SiC), and indium phosphide (InP). The laser generated by the photonic crystal layer 21 is emitted from the surface of the light-transmitting substrate 26 away from the Bragg reflector 24.

[0084] In this embodiment, the light-emitting module 2 further includes a first electrode 28 and a second electrode 29 which are electrically insulated from each other. The first electrode 28 and the second electrode 29 are used to receive the driving signal. The first electrode 28 and the second electrode 29 are made of metal, such as titanium (Ti), germanium (Ge), nickel (Ni), gold (Au), or platinum (Pt), or an alloy thereof. In this embodiment, the first electrode 28 is an N-type electrode, and the second electrode 29 is a P-type electrode.

[0085] The first electrode 28 is located on one side of the Bragg reflector 24 away from the light-transmitting substrate 26 and directly contacts the Bragg reflector 24. The second electrode 29 includes a first conductive part 291 and a second conductive part 292.

[0086] The first conductive part 291 is located on one side of the Bragg reflector 24 away from the light-transmitting substrate 26. The first conductive part 291 is flush with the surface of the first electrode 28 away from the light-transmitting substrate 26. That is, the first conductive part 291 is coplanar with the first electrode 28.

[0087] The first conductive part 291 encloses a first accommodation space S1 having a gap S0. The first electrode 28 includes a third conductive part 281, a fourth conductive part 282, and an extension part 283 connecting the third conductive part 281 and the fourth conductive part 282. The third conductive part 281 is located in the first accommodation space S1, the fourth conductive part 282 is located outside the first accommodation space S1, and the extension part 283 extends from the third conductive part 281 to the fourth conductive part 282 through the gap S0. The third conductive part 281 is spaced apart from the first conductive part 291 to be electrically insulated.

[0088] Please refer to Figure 3 and Figure 4The second conductive part 292 is formed by extending the first conductive part 291 toward the light-transmitting substrate 26. The second conductive part 292 has a hollow space S2. The transparent conductive layer 25, the photonic crystal layer 21, the active light-emitting layer 22, the first cladding layer 23, and the Bragg reflector 24 are located in the hollow space S2. The thermally conductive adhesive layer 27 covers the end surface of the second conductive part 292 close to the light-transmitting substrate 26, part of the outer surface of the second conductive part 292 (the surface away from the hollow space S2), and the transparent conductive layer 25. The end of the second conductive part 292 close to the light-transmitting substrate 26 is in electrical contact with the transparent conductive layer 25.

[0089] In the embodiment, the light-emitting module 2 further includes an insulating layer 20. The insulating layer 20 can be silicon nitride (SiNx), silicon dioxide (SiO2), or polymethyl methacrylate (PMMA). The insulating layer 20 is located in the hollow space S2 formed by the second conductive part 292 and partially adheres to the inner wall 2921 of the second conductive part 292. The insulating layer 20 is located between the photonic crystal layer 21, the active light-emitting layer 22, the first cladding layer 23, the Bragg reflector 24, and the second conductive part 292.

[0090] The part of the insulating layer 20 not adhering to the inner wall 2921 of the second conductive part 292 has a gap with the inner wall 2921, and the transparent conductive layer 25 is filled in the gap to be in electrical contact with the second conductive part 292.

[0091] The insulating layer 20 also extends to the side of the Bragg reflector 24 away from the light-transmitting substrate 26 and is located between the first electrode 28 and the first conductive part 291, so that the first electrode 28 is spaced apart from the first conductive part 291 to be electrically insulated.

[0092] When the first electrode 28 and the second electrode 29 are respectively applied with driving signals (the driving signals applied to the first electrode 28 and the second electrode 29 have different sizes), the driving current is injected from the side of the photonic crystal layer 21 close to the light-transmitting substrate 26. The active light-emitting layer 22 generates photons under the driving of the driving current. The photons generated by the active light-emitting layer 22 repeatedly oscillate in the photonic crystal layer 21 when propagating to the photonic crystal layer 21, until the light-emitting module 2 reaches a gain and loss balance to generate laser, and the laser is emitted from the side of the light-transmitting substrate 26 away from the Bragg reflector 24.

[0093] In the above process, the first cladding layer 23, the second cladding layer 212, and the Bragg reflector 24 are all used to prevent photons from being emitted from the side away from the light-transmitting substrate 26, which is beneficial to improving the light utilization and thus improving the light-emitting power of the light-emitting module 2.

[0094] In the above process, the first cladding layer 23, the second cladding layer 212, and the Bragg reflector 24 are all used to prevent photons from being emitted from the side away from the light-transmitting substrate 26, which is beneficial to improving the light utilization and thus improving the light-emitting power of the light-emitting module 2. Figure 2From this perspective, the third conductive portion 281, the fourth conductive portion 282, and the extension portion 283 are all rectangular. The first conductive portion 291 is a rectangular frame with a notch S0 that conforms to the shape of the third conductive portion 281. The receiving space S1 is filled with an insulating layer 20 to electrically insulate the third conductive portion 281 from the first conductive portion 291.

[0095] In other embodiments of this application, in Figure 2 From a certain perspective, the third conductive portion 281 and the first conductive portion 291 can have other shapes. For example... Figure 5 As shown, the third conductive part 281 can be circular, and the first conductive part 291 is an annular shape with a notch S0 that is adapted to the shape of the third conductive part 281.

[0096] In this embodiment, the third conductive part 281 is Figure 2 The shape of the third conductive part 281 as seen from the viewpoint is the same as the projection shape of the third conductive part 281 onto the active light-emitting layer 22. The third conductive part 281 is positioned directly opposite the photonic crystal layer 21, such that the projection of the third conductive part 281 onto the active light-emitting layer 22 completely covers the projection of the photonic crystal layer 21 onto the active light-emitting layer 22. That is, the projection of the third conductive part 281 onto the active light-emitting layer 22 has the same area as the projection of the photonic crystal layer 21 onto the active light-emitting layer 22 and completely overlaps, or the projection area of ​​the third conductive part 281 onto the active light-emitting layer 22 is larger than the projection of the photonic crystal layer 21 onto the active light-emitting layer 22.

[0097] Because there are multiple periodically distributed vias 213 in the photonic crystal layer 21, the impedance is higher at the locations where vias 213 are formed and lower at the locations where no vias are formed. This impedance difference at various locations in the photonic crystal layer 21 may cause the driving current to vary in the horizontal direction (within the range of vias 213). Figure 3 or Figure 4 (Based on) uneven diffusion. In this embodiment, when the first electrode 28 receives a driving signal, the position and shape of the third conductive portion 281 of the first electrode 28 are conducive to making the driving current diffuse unevenly in the horizontal direction (based on) Figure 3 or Figure 4 (Based on) uniform diffusion.

[0098] Please see Figure 6 and Figure 7 The driving module 3 is a transistor. In this embodiment, the driving module 3 is a high electron mobility transistor (HEMT): gallium nitride transistor.

[0099] The driving module 3 includes a substrate 31, a buffer layer 32, a channel layer 33 and an electrode layer 34 stacked in sequence.

[0100] The material of the substrate 31 is sapphire, silicon, silicon oxide, silicon carbide or diamond. The substrate 31 is used to support the buffer layer 32, the channel layer 33 and the electrode layer 34 in the process. The buffer layer 32 is located on a surface of the substrate 31, and the material can be gallium nitride or aluminum gallium nitride.

[0101] The channel layer 33 includes a P-type gallium nitride layer 331, an aluminum gallium nitride barrier layer 332 and an undoped gallium nitride channel 333 which are sequentially stacked.

[0102] The material of the electrode layer 34 can be titanium (Ti), aluminum (Al), nickel (Ni), gold (Au) or palladium (Pd). The electrode layer 34 includes a gate G, a source S, a drain D and a connection electrode P. The gate G, the source S, the drain D and the connection electrode P are spaced apart from each other to be insulated. In this embodiment, the driving module 3 further includes an insulating material layer 35 located between the gate G, the source S, the drain D and the connection electrode P to space apart the gate G, the source S, the drain D and the connection electrode P.

[0103] The P-type gallium nitride layer 331 is in direct contact with the gate G, and the P-type gallium nitride layer 331 is insulated from the source S, the drain D and the connection electrode P by the insulating material layer 35. The aluminum gallium nitride barrier layer 332 and the undoped gallium nitride channel 333 are in contact with the source S and the drain D, respectively.

[0104] The drain D is in electrical contact with the first electrode 28 to apply a negative voltage to the first electrode 28. The connection electrode P is in electrical contact with the second electrode 29 to apply a positive voltage to the second electrode 29. The positive voltage and the negative voltage are the driving signal described above, which causes the first electrode 28 and the second electrode 29 to have a voltage difference, forms a current loop in the light emitting module 2, that is, forms a driving current to emit laser. The undoped gallium nitride channel 333 serves as a main conduction semiconductor channel, and the P-type gallium nitride layer 331 is beneficial to increase the barrier height of the aluminum gallium nitride barrier layer 332 above the Fermi level.

[0105] The drain D and the first electrode 28, and the connection electrode P and the second electrode 29 are fixed by an intermetallic bonding method. The intermetallic bonding method is, for example, a gold-to-gold face-to-face bonding technique.

[0106] In other embodiments, the driving module 12 does not include the connection electrode P, and the second electrode 29 is directly in electrical contact with the gate G, and the gate G provides the driving signal for the second electrode 29. That is, the voltage on the gate G is used as the driving signal for the second electrode 29. Compared with electrically connecting the second electrode 29 through the connection electrode P, it is beneficial to reduce the step of forming the connection electrode P.

[0107] When the voltage on the gate G reaches the turn-on voltage of the driving module 3, the channel layer 33 is turned on, and the source S and drain D are electrically connected. A negative voltage (driving signal) is applied to the drain D via the first electrode 28. The connecting electrode P is used to receive a positive voltage (driving signal) and to apply the positive voltage to the second electrode 29. The light emitting module 2 emits laser light under the drive signal.

[0108] In the aforementioned photonic crystal surface-emitting laser device 10, the driving module 3 and the light-emitting module 2 are integrated. The driving module 3 is a gallium nitride transistor with high electron mobility (in some embodiments, the electron mobility can be above 2000 cm² / V·s), which is beneficial for improving the switching speed of the photonic crystal surface-emitting laser device 10. The light-emitting module 2 generates heat during operation. Since the light-emitting module 2 in this embodiment does not include a substrate, that is, the first electrode 28 and the second electrode 29 of the light-emitting module 2 are directly bonded to the electrode layer 34 of the driving module 3 without being separated by a substrate, which is beneficial for the heat dissipation of the light-emitting module 2. Therefore, it is beneficial for improving the luminous power and lifespan of the photonic crystal surface-emitting laser device 10.

[0109] The following simulation compares the heat dissipation effects of the photonic crystal surface-emitting laser in the comparative example with the photonic crystal surface-emitting laser 100 in this application.

[0110] Figure 8 The operating temperature T of a photonic crystal surface-emitting laser at an ambient temperature of 360K. max Curve showing the variation of drive current. Figure 8 Curve X represents the photonic crystal surface-emitting laser in the first pair of examples, curve Y represents the photonic crystal surface-emitting laser in the second pair of examples, and curve Z represents the photonic crystal surface-emitting laser in this application. Figure 8 It can be seen that, under the same ambient temperature and with equal driving current, the temperature corresponding to curve Z is the lowest, which means that the photonic crystal surface-emitting laser in this application has the lowest operating temperature and the best heat dissipation effect.

[0111] Figure 9 The operating temperature T of the photonic crystal surface-emitting laser in the first comparative example. max Curve showing the variation of drive current. Figure 9 Curves X1, X2, X3, and X4 represent the operating temperature as a function of drive current at ambient temperatures Tc = 300K, 320K, 340K, and 360K, respectively.

[0112] Figure 10 The operating temperature T of the photonic crystal surface-emitting laser in the second comparative example. max Curve showing the variation of drive current. Figure 10The curves Y1, Y2, Y3 and Y4 are working temperature-current curves at ambient temperatures Tc=300K, 320K, 340K and 360K, respectively.

[0113] Figure 11 The working temperature T of the photonic crystal surface-emitting laser in the embodiment of the present application max The working temperature T of the photonic crystal surface-emitting laser in the embodiment of the present application Figure 11 The curves Z1, Z2, Z3 and Z4 are working temperature-current curves at ambient temperatures Tc=300K, 320K, 340K and 360K, respectively.

[0114] Therefore, at any same ambient temperature, when the driving current is equal, the temperature corresponding to the curve Z (Z1, Z2, Z3 and Z4) is the minimum, that is, the working temperature of the photonic crystal surface-emitting laser in the embodiment of the present application is the minimum, and the heat dissipation effect is the best.

[0115] The driving module 3 is integrated with the light emitting module 2, and the substrate is omitted, which is also beneficial to the miniaturization of the structure. The first electrode 28 and the second electrode 29 are coplanarly arranged, the electric connection is realized without setting a punching area, and the area of the light emitting module 2 is also reduced, and the parasitic capacitance and inductance generated in the punching area are avoided.

[0116] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application, and are not used as a limitation to the present application, and any appropriate changes and variations to the above embodiments within the scope of the spirit of the present application are within the scope of the present application.

Claims

1. A photonic crystal surface-emitting laser device, characterized in that, include: The optical emitting module includes: Photonic crystal layer; An active light-emitting layer is located on one side of the photonic crystal layer; The first electrode is located on the side of the active light-emitting layer away from the photonic crystal layer; and The second electrode is at least partially located on the side of the active light-emitting layer away from the photonic crystal layer; and The driving module is electrically contacted with the surfaces of the first electrode and the second electrode away from the photonic crystal layer, respectively, and is used to output driving signals to the first electrode and the second electrode to drive the active light-emitting layer to generate photons. The photons are incident on the photonic crystal layer and undergo Bragg diffraction oscillation to generate laser light. The first electrode and the second electrode of the light-emitting module are directly connected to the driving module.

2. The photonic crystal surface-emitting laser device as described in claim 1, characterized in that, The second electrode includes a first conductive portion and a second conductive portion that are electrically connected to each other; The first conductive portion is located on the side of the active light-emitting layer away from the photonic crystal layer, and the second conductive portion extends along the outer edge of the first conductive portion toward the photonic crystal layer. The second conductive portion is a cylindrical structure including a hollow space, and the photonic crystal layer and the active light-emitting layer are located in the hollow space.

3. The photonic crystal surface-emitting laser device as described in claim 2, characterized in that, The light emitting module further includes a transparent conductive layer, which is located on the side of the photonic crystal layer away from the active light-emitting layer and within the hollow space; The second conductive portion of the second electrode is in electrical contact with the transparent conductive layer at one end near the photonic crystal layer.

4. The photonic crystal surface-emitting laser device as described in claim 2, characterized in that, The first electrode includes a third conductive portion, the orthographic projection of which on the active light-emitting layer completely covers the orthographic projection of the photonic crystal layer on the active light-emitting layer.

5. The photonic crystal surface-emitting laser device as described in claim 4, characterized in that, The first conductive portion of the second electrode encloses a receiving space with a notch, and the third conductive portion of the first electrode is located within the receiving space.

6. The photonic crystal surface-emitting laser device as described in any one of claims 1 to 5, characterized in that, The driving module is a transistor.

7. The photonic crystal surface-emitting laser device as described in claim 6, characterized in that, The driving module is a gallium nitride transistor.

8. The photonic crystal surface-emitting laser device as described in claim 6, characterized in that, The driving module includes an electrode layer, which includes a gate, a source, and a drain that are spaced apart and insulated from each other. The gate is electrically connected to the second electrode, and the drain is electrically connected to the first electrode. When the voltage on the gate is greater than the threshold voltage of the driving module, the source and the drain are turned on, and the drain and the gate are used to apply the driving signal to the first electrode and the second electrode.

9. The photonic crystal surface-emitting laser device as described in claim 6, characterized in that, The driving module includes an electrode layer, which includes a gate, a source, a drain, and a connecting electrode that are spaced apart and insulated from each other. When the drain is electrically connected to the first electrode, and the voltage on the gate is greater than the threshold voltage of the driving module, the source and the drain are turned on, and the drain is used to apply the driving signal to the first electrode; The connecting electrode makes electrical contact with the second electrode and is used to apply the driving signal to the second electrode.

10. An optical system, characterized in that, include: The photonic crystal surface-emitting laser device as described in any one of claims 1 to 9; and A control device, electrically connected to the photonic crystal surface-emitting laser device, is used to output the driving signal to the photonic crystal surface-emitting laser device to drive the photonic crystal surface-emitting laser device to emit laser light.

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