CN112952551B - Surface emitting laser element with mixed grating structure and its making process - Google Patents

Abstract

The grating layer of the surface-emitting laser element is divided into a first grating region and a second grating region in at least a first horizontal direction. The second grating region is located in a middle region of the grating layer, and the first grating region is located in an outer region of the grating layer. Each of the first grating region and the second grating region comprises a plurality of micro-grating structures. The grating periods of the micro-grating structures in the first grating region conform to the following mathematical formula:

and, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula:

wherein lambda is the grating period length, lambda is the lasing wavelength of the laser, n _eff Is the equivalent refractive index of the semiconductor waveguide, m=1 and o=2. Therefore, the first grating region is a first-order grating structure region, and the second grating region is a second-order grating structure region, so as to form a hybrid grating structure on the grating layer. The surface emitting laser element is a light emitting surface defined by the second grating region for emitting laser vertically.

Description

Surface emitting laser element with hybrid grating structure and its manufacturing method

technical field

The present invention relates to a surface-emitting laser element with a hybrid grating structure and its manufacturing method, especially to a hybrid grating composed of a first-order grating structure area and a second-order grating structure area in the grating layer. A surface-emitting laser element and its manufacturing method.

Background technique

Semiconductor laser (semiconductor laser) or laser diode (laser diode) has the advantages of small size, low power consumption, fast response, impact resistance, long life, high efficiency and low price, so it is widely used in optoelectronic system products Among them, for example: light wave communication, information system, household appliances, precision measurement and optical fiber communication, etc. Among them, Distributed Feedback Laser (DFB Laser) has the characteristics of simple manufacturing process, single-mode output and suitable for long-distance transmission. The laser signal generated by distributed feedback laser can still maintain a good signal after long-distance transmission. Therefore, it has become a widely used light source in today's light wave communication and optical fiber communication systems.

Please refer to FIG. 1 , which is a schematic cross-sectional view of a typical surface emitting distributed feedback laser (Surface Emitting Distributed Feedback Laser: SE-DFB laser for short), which sequentially includes from bottom to top: a semiconductor substrate 91, a lower cladding layer (cladding layer) ), a separate confinement hetero-structure (SCH) layer, an active region layer 92 (active region layer), an upper confinement layer, a spacer layer, a grating layer 93, an upper cladding layer 94, and a contact layer. According to the difference in the design of the period of most micro-grating structures contained in the grating layer, SE-DFB lasers can generally be classified as adopting the first-order grating structure design or adopting the second-order grating structure design. The so-called first-order or second-order grating structure design is determined according to the following formula:

Among them, ∧ is the period (grating period) length of two adjacent micro-grating structures, λ is the wavelength (wavelength) of the laser light emitted by the SE-DFB laser, n _eff is the equivalent refractive index of the semiconductor waveguide (effective refractive index), and m is the so-called "order" value. It can be seen that when m=1, the period value ∧ of the micro-grating structure roughly corresponds to one-half of the laser wavelength λ (that is, λ/2), and the micro-grating structures included in the grating layer can be called First order grating structure (First order grating). When m=2, the period value ∧ of the micro-grating structure roughly corresponds to the laser wavelength λ (that is, λ), and the micro-grating structures contained in the grating layer are called second-order grating structures. At this time, there will be first-order and second-order diffraction, corresponding to the coupling constant (coupling constant) K1 (related to the surface light emission efficiency) and K2 (related to the in-plane cavity efficiency).

Assuming that the micro-grating structure is a teeth-like shape (as shown in Figure 1), the in-plane resonant cavity coupling constant (K _m ) obtained by designing the grating structure of different orders, K _m is proportional to Sin[π*m*ratio ]/(π*m). Among them, m is the "order (order)"value; ratio (ratio) refers to the duty cycle of the grating, that is, ratio=a/∧ as shown in Figure 1; where a is two adjacent micro-gratings The gap value of the structure. Please refer to FIG. 2 , which is a graph comparing the relationship between the ratio value and the in-plane resonant cavity coupling constant (K _m ) value when m=1 and m=2. It can be seen from Figure 2 that comparing the curves of m=1 (first-order grating structure) and m=2 (second-order grating structure), it can be seen that the efficiency of the in-plane resonant cavity formed by the second-order grating structure is generally higher than that of the first-order grating structure. The structure comes low.

The SE-DFB laser formed according to the second-order grating structure design has many advantages, such as a small exit angle, and can be tested and burn-in in the wafer state. Moreover, unlike general edge emitting DFB lasers that require mirror splitting and coating, the principle of the SE-DFB laser formed according to the second-order grating structure design is to make a micro-grating structure with a period value of λ/n _eff , In this way, the second-order diffraction of the micro-grating structure is used on the in-plane to couple the forward and backward modes in the waveguide to form a resonant cavity to emit Laser (lasing), and the laser is coupled out from the top surface of the SE-DFB laser.

Due to the SE-DFB laser formed by the design of the second-order grating structure, the first-order and second-order occur simultaneously in the optical mode (optical mode), except for the above-mentioned low-efficiency second-order diffraction as a resonant cavity Feedback (cavity feedback), and additional first-order diffracted light output coupling loss (light output coupling loss), so that such components often require a larger area and a larger threshold current (Ith) to operate, This is its shortcoming.

For this reason, the present invention provides a novel design of surface emitting distributed feedback laser, which integrates the first-order and second-order grating structures in the same grating layer. The low-loss first-order grating structure design is used to serve as a high-efficiency reflection feedback (feedback) area placed on the laser end face, and the second-order grating structure design is used only in the light-emitting area near the middle laser surface. In this way, it is possible to achieve the desired value between the pursuit of high slope efficiency (meaning a larger second-order grating structure area) and low critical current value Ith (meaning a smaller second-order grating structure area) balance. In the center of the second-order grating structure region, a λ/4-Shift phase difference grating structure can also be introduced, so that the laser field can be modal stabilized and the light efficiency of the optocoupler can be improved.

Contents of the invention

The main purpose of the present invention is to provide a surface-emitting laser element with a hybrid grating structure and its manufacturing method, by setting a hybrid grating composed of a first-order grating structure region and a second-order grating structure region in the grating layer The structure can achieve a desired balance between pursuing high slope efficiency (slope efficiency) and low critical current value Ith. Moreover, a λ/4-Shift phase difference grating structure can also be introduced in the center of the second-order grating structure region, so that the laser field can be modal stabilized and the optical efficiency of the optocoupler can be improved.

Another object of the present invention is to provide a surface emitting laser element, which converts the same concept of the aforementioned main object from a one-dimensional grating structure to a two-dimensional photonic crystal surface emitting laser (PCSEL for short). The first-order photonic crystals are deployed around the laser element, and the second-order photonic crystals are only deployed in the middle of the light output, and a phase difference structure is properly introduced to operate the mode. It is also possible to deploy several light outlets at the same time (that is, only deploy the second-order photonic crystals at the light outlets) to achieve an effect similar to that of a 2D array phase lock with multiple light sources.

To achieve the above object, the present invention provides a surface-emitting laser element with a hybrid grating structure, which can produce laser light with a laser wavelength; the surface-emitting laser element includes:

A semiconductor stack structure, capable of generating the laser light with the laser wavelength when receiving an electric current, and causing the laser light to emit from a light-emitting surface of the semiconductor stack structure, and the light-emitting surface is located on a top surface of the semiconductor stack structure;

A grating layer, located on the semiconductor stack structure, the grating layer has a plurality of micro-grating structures distributed and arranged along at least one first horizontal direction;

并且，该第二光栅区内的多个该微光栅结构的光栅周期是符合以下数学式：/>

其中，∧是光栅周期长度，λ是该激光的该激光波长，n_eff是半导体波导的等效折射率，m和o都是正整数，m和o不相等，且o为m的偶数倍；Wherein, the grating layer is distinguished at least in the first horizontal direction to include: at least one first grating area and at least one second grating area, and each of the first grating area and the second grating area contains a plurality of The micro-grating structure; wherein, the grating period of the plurality of micro-grating structures in the first grating area is in accordance with the following mathematical formula:

In addition, the grating period of the plurality of micro-grating structures in the second grating area is in accordance with the following mathematical formula: />

Wherein, ∧ is the period length of the grating, λ is the laser wavelength of the laser, n _eff is the equivalent refractive index of the semiconductor waveguide, m and o are both positive integers, m and o are not equal, and o is an even multiple of m;

Wherein, the light emitting surface is defined by the second grating area.

In one embodiment, m=1 and o=2; therefore, the first grating area is also called a first-level grating structure area, and the second grating area is also called a second-level grating structure area, whereby A hybrid grating structure is formed on the grating layer; wherein, the laser light is emitted vertically from the light-emitting surface defined by the second grating area.

In one embodiment, the grating layer further includes a phase difference grating structure; the phase difference grating structure is located near the middle of the second grating region in the first horizontal direction, and the phase difference grating structure The width can provide a phase difference distance, so that there is a phase difference between the plurality of micro-grating structures located on both sides of the phase difference grating structure in the first horizontal direction; the phase difference provided by the phase difference grating structure The difference distance is a quarter of the laser wavelength.

In one embodiment, the number of the second grating area is one and is located in a middle area of the grating layer in the first horizontal direction, so that the first grating area is substantially surrounded by the second grating located in the middle The area is divided into left and right parts in the first horizontal direction; wherein, the width of the second grating area in the first horizontal direction is between one-sixth and one-half of the total width of the grating layer Width; the widths of the left and right parts separated by the first grating area are substantially equal.

In one embodiment, the grating layer also has a plurality of micro-grating structures along a second horizontal direction, the second horizontal direction is perpendicular to the first horizontal direction; the grating layer is in the second horizontal direction It is also divided into at least one of the first grating area and at least one of the second grating area, and each of the first grating area and the second grating area contains a plurality of the micro-grating structures; thereby, when the vertical Viewed in the direction of the top surface of the semiconductor stack structure, the plurality of micro-grating structures are arranged in a dot-like array on the grating layer, and the second grating region and the second grating in the first horizontal direction Both the second grating regions in the horizontal direction cooperate to define a rectangular at least one light-emitting surface.

In one embodiment, the grating layer further includes two phase difference grating structures; one of the phase difference grating structures is located near the middle of the second grating region in the first horizontal direction, and the other is the phase difference grating structure. The phase difference grating structure is located near the middle of the second grating area in the second horizontal direction; and the width of the phase difference grating structure can provide a phase difference distance, so that the first horizontal direction and the There is a phase difference between the micro-grating structures located on both sides of the phase difference grating structure in the second horizontal direction; the phase difference distance provided by the phase difference grating structure is a quarter of the laser wavelength.

In one embodiment, the second grating region is located in an intermediate region of the grating layer in the first horizontal direction and the second horizontal direction; when viewed from a direction perpendicular to the top surface of the semiconductor stack structure , the second grating region is located in a central region of the top surface of the semiconductor stack structure, and the first grating region substantially surrounds the outer peripheral region of the second grating region; wherein, the second grating region The widths in the first horizontal direction and the second horizontal direction are respectively between one-sixth and one-half of the total width of the grating layer in the first horizontal direction and the second horizontal direction.

In one embodiment, the top surface of the semiconductor stack structure includes a plurality of independent light-emitting surfaces arranged in an array, and the grating layer is located on each of the light-emitting surfaces whether in the first horizontal direction or the The second grating area is set in the second horizontal direction, and the other areas of the grating layer except for the plurality of light-emitting surfaces are set in the first horizontal direction or in the second horizontal direction. A grating area; whereby a plurality of small light-emitting surfaces that are independent and arranged in an array can be defined on the top surface of the semiconductor stack structure.

In order to achieve the above object, the present invention provides a method for preparing a surface-emitting laser element with a hybrid grating structure, comprising the following steps:

Step (A): A semiconductor stack structure is formed on a semiconductor substrate by a semiconductor epitaxy process; the semiconductor stack structure can generate a laser with a laser wavelength when receiving an electric current, and the laser light is emitted from the semiconductor stack A light-emitting surface of the structure is emitted, and the light-emitting surface is located on a top surface of the semiconductor stack structure;

Step (B): forming a grating layer on the semiconductor stacked structure by electron beam printing and nanoimprinting process, and is located on the semiconductor stacked structure; the grating layer has elements arranged along at least one first horizontal direction Multiple micro-grating structures;

Step (C): forming an upper cladding layer and a contact layer on the grating layer by semiconductor epitaxy process and photolithography process, and are located above the grating layer;

并且，该第二光栅区内的多个该微光栅结构的光栅周期是符合以下数学式：/>

其中，∧是光栅周期长度，λ是该激光的该激光波长，n_eff是半导体波导的等效折射率，m和o都是正整数，m和o不相等，且o为m的偶数倍；Wherein, the grating layer is distinguished at least in the first horizontal direction to include: at least one first grating area and at least one second grating area, and each of the first grating area and the second grating area contains a plurality of The micro-grating structure; wherein, the grating period of the plurality of micro-grating structures in the first grating area is in accordance with the following mathematical formula:

In addition, the grating period of the plurality of micro-grating structures in the second grating area is in accordance with the following mathematical formula: />

Wherein, ∧ is the period length of the grating, λ is the laser wavelength of the laser, n _eff is the equivalent refractive index of the semiconductor waveguide, m and o are both positive integers, m and o are not equal, and o is an even multiple of m;

Wherein, the light emitting surface is defined by the second grating area.

To achieve the above object, the present invention provides a surface-emitting laser element that can produce laser light with a laser wavelength, and the surface-emitting laser element includes:

A semiconductor stack structure, capable of generating the laser light with the laser wavelength when receiving an electric current, and causing the laser light to emit from a light-emitting surface of the semiconductor stack structure, and the light-emitting surface is located on a top surface of the semiconductor stack structure;

并且，该第二光子晶体区内的多个该微光子晶体结构的光子晶体周期是符合以下数学式：/>

其中，∧是光子晶体周期长度，λ是该激光的该激光波长，n_eff是半导体波导的等效折射率，m和o都是正整数，m和o不相等，且o为m的偶数倍；A photonic crystal layer located on the semiconductor stack structure, the photonic crystal layer has a plurality of micro-photonic crystal structures distributed and arranged along a first horizontal direction and a second horizontal direction, the second horizontal direction and the first horizontal direction The horizontal direction is vertical; wherein, the photonic crystal layer is divided in the first horizontal direction and the second horizontal direction to include: at least one first photonic crystal region and at least one second photonic crystal region, in each of the first The photonic crystal region and the second photonic crystal region respectively contain a plurality of the micro-photonic crystal structures; wherein, the photonic crystal periods of the plurality of micro-photonic crystal structures in the first photonic crystal region conform to the following mathematical formula:

Moreover, the photonic crystal periods of the plurality of micro-photonic crystal structures in the second photonic crystal region conform to the following mathematical formula: />

Wherein, ∧ is the period length of the photonic crystal, λ is the laser wavelength of the laser, n _eff is the equivalent refractive index of the semiconductor waveguide, m and o are both positive integers, m and o are not equal, and o is an even multiple of m;

Wherein, the light emitting surface is defined by the second photonic crystal region.

In one embodiment, the photonic crystal layer further includes two phase-difference photonic crystal structures; one of the phase-difference photonic crystal structures is located near the middle of the second photonic crystal region in the first horizontal direction , another phase difference photonic crystal structure is located near the middle of the second photonic crystal region in the second horizontal direction; and the width of the phase difference photonic crystal structure can provide a phase difference distance, so that There is a phase difference between the multiple micro-photonic crystal structures located on both sides of the phase difference photonic crystal structure in the first horizontal direction and the second horizontal direction; the phase difference distance provided by the phase difference photonic crystal structure is a quarter of the laser wavelength.

In one embodiment, the top surface of the semiconductor stack structure includes a plurality of independent light-emitting surfaces arranged in an array, and the photonic crystal layer is located on each of the light-emitting surfaces whether in the first horizontal direction or The second photonic crystal region is arranged in the second horizontal direction, and other regions of the photonic crystal layer except for the plurality of light-emitting surfaces are arranged in the first horizontal direction or the second horizontal direction The first photonic crystal region; thereby, a plurality of small light-emitting surfaces that are independent and arranged in an array can be defined on the top surface of the semiconductor stack structure.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a typical Surface Emitting Distributed Feedback Laser (Surface Emitting Distributed Feedback Laser: SE-DFB laser for short).

FIG. 2 is a graph comparing the relationship between the ratio value (ratio) and the coupling constant (K _m ) of the in-plane resonant cavity when m=1 and m=2.

Fig. 3A, Fig. 3B and Fig. 3C are respectively the three-dimensional schematic diagram, the cross-sectional schematic diagram and the grating of the first embodiment of the Surface Emitting Distributed Feedback Laser element (Surface Emitting Distributed Feedback Laser, referred to as SE-DFB Laser) with a hybrid grating structure of the present invention Layer top view diagram.

Fig. 4 is a schematic diagram of the grating layer of a typical edge-firing DFB laser element.

Fig. 5A to Fig. 5D show the intensity distribution curves of the laser guided mode along the ridge obtained by simulating the laser element according to the first embodiment of the present invention by changing the length of L2 from 0 μm, 50 μm, 100 μm to 150 μm, respectively. ; Wherein, L2 is the length of the second grating area.

Figures 6A to 6D show the normalized gain (g*L) and Detuning relationship (δL) relationship curve.

Fig. 7 is a graph showing the relationship between the critical gain (Threshold gain) and different L2 lengths obtained by simulating the laser element of the first embodiment of the present invention by changing the L2 length from 0 μm, 50 μm, 100 μm to 150 μm in four structural changes .

8 and 9 are a perspective view and a top view of a grating layer, respectively, of a second embodiment of a surface-emitting laser device of the present invention.

FIG. 10 is a schematic top view of the grating (or photonic crystal) layer of the third embodiment of the surface-emitting laser element with the hybrid grating (or photonic crystal) structure of the present invention.

FIG. 11 is a schematic top view of the grating layer of the fourth embodiment of the surface-emitting laser device with a hybrid grating (or photonic crystal) structure according to the present invention.

12A and 12B are schematic diagrams of micro-grating structures of a conventional distributed feedback laser device with a pure first-order grating structure and a surface-emitting laser device with a first-order and second-order hybrid grating structure according to the present invention, respectively.

13A to 13C are schematic diagrams of several steps in the manufacturing method of the surface-emitting laser device with a hybrid grating structure according to the present invention.

FIG. 14 is a schematic perspective view of a fifth embodiment of a surface-emitting laser device with a hybrid grating structure according to the present invention.

List of reference signs:

10～substrate 11～lower cladding layer

12～low light confinement layer 13～active layer

14～glazing limited layer

16 ~ grating layer 162 ~ first grating area

163～second grating area 164～phase difference grating structure

17～upper cladding layer 18～contact layer

191, 192～metal layer 21～light emitting surface

Detailed ways

In order to more clearly describe the surface-emitting laser element with a hybrid grating structure proposed by the present invention and

The manufacturing method will be described in detail below in conjunction with the drawings.

Please refer to Fig. 3A, Fig. 3B and Fig. 3C, which are respectively the three-dimensional schematic diagram and cross-section of the first embodiment of the Surface Emitting Distributed Feedback Laser (Surface Emitting Distributed Feedback Laser, referred to as SE-DFB Laser) with a hybrid grating structure of the present invention Schematic and top view of the grating layer. As shown in FIG. 3A, FIG. 3B and FIG. 3C, in the first embodiment, the surface emitting distributed feedback (SE-DFB) laser element of the present invention can be roughly divided into structures including: a semiconductor stack structure, a A grating layer (Grating) 16 , and two metal layers 191 , 192 . Wherein, the semiconductor stack structure can generate laser light with a laser wavelength of λ when receiving a predetermined current, and make the laser emit vertically upward from a light exit surface 21 of the semiconductor stack structure, and the light exit surface 21 is located on the semiconductor stack structure A top surface, so it conforms to the structure of a general surface-emitting laser diode element. The grating layer 16 is located on the semiconductor stack structure, and the grating layer 16 includes a plurality of micro-grating structures distributed and arranged along at least one first horizontal direction.

In this embodiment, the semiconductor stack structure includes: a semiconductor substrate 10, a cladding layer 11 (cladding layer) on the semiconductor substrate 10, and a light confinement layer 12 (Separated Confinement Hetero-Structure; SCH for short) on the On the lower cladding layer 11, an active region layer 13 (active region layer) is located on the lower optical confinement layer 12, an upper optical confinement layer 14 is located on the active layer 13, and a spacer (Spacer; not shown in the figure) Located on the glazing confinement layer 14 . Wherein, the grating layer 16 is located on the spacer layer; and the semiconductor stack structure further includes: an upper cladding layer 17 is located on the grating layer 16, and a contact layer 18 (Contact) is located on the upper cladding layer 17 superior. The upper metal layer 192 is located above the contact layer 18 , and the lower metal layer 191 is located below the substrate 10 .

The operating principle of the general distributed feedback laser diode element is that carriers such as electrons and holes are injected into the active layer, and are confined by the carrier barrier (Barrier) in the quantum well (Quantum Well) to recombine and emit light to generate material gain. The limiting principle is that the barrier layer has a higher material energy gap than the quantum well layer, so a lower quantum energy level will be formed in the quantum well, and once the carrier is captured, it will not be easy to escape. The laser field is confined by the upper and lower cladding layers in a rectangular narrow resonant cavity formed by the upper and lower SCH layers and the active layer. The limiting principle is that the upper and lower cladding layers have a lower optical refractive index n value (Low Refractive Index) than the upper, lower SCH layer and active layer, and the light field will use the principle of total reflection in materials with relatively high n values Modes are formed and propagated. The degree of coupling between the optical field and the quantum well of the active layer determines the modal gain (Modal Gain). The higher the modal gain, the easier it is to overcome the optical loss (Optical Loss) to achieve lasing (Lasing), and the easier it is to reduce the generation of laser The threshold current value (or called pumping threshold current; Threshold Current).

In an embodiment of the present invention, the semiconductor substrate 10 may be an indium phosphide (InP) substrate, and the lower cladding layer 11, the The lower optical confinement layer 12 , the active layer 13 , the upper optical confinement layer 14 , and the upper cladding layer 17 . Wherein, the InP substrate 10 , the lower cladding layer 11 , and the lower optical confinement layer 12 all have n-type doping. Both the upper cladding layer 17 and the contact layer 18 have p-type doping. The material of the lower cladding layer 11 and the upper cladding layer 17 is InP. The material of the active layer 13 may be In _{1-x- y} Al _x Ga _y As, where x and y are real numbers between 0 and 1. The material of the contact layer 18 may be InGaAs. The material of the lower optical confinement layer 12 and the upper optical confinement layer 14 may be In _1-z Al _z As, wherein z is a real number between 0 and 1. Because the parameters such as the material composition, structure thickness, and doping concentration of each layer in the semiconductor stack structure of the present invention described herein can be selected from the known parameters of the conventional distributed feedback laser, and are not the technical characteristics of the present invention, Therefore, the details are not repeated, and parameters such as material composition, structure thickness, and doping concentration of each layer in the semiconductor stack structure of the present invention are not limited to the embodiments described in this paragraph.

并且，该第二光栅区163内的多个该微光栅结构的光栅周期是符合以下数学式：/>

其中，∧是光栅周期长度，λ是该激光的该激光波长，n_eff是半导体波导的等效折射率，m和o都是正整数，m和o不相等，且o为m的偶数倍。其中，该出光面21是由该第二光栅区163所定义。于第一实施例中，m＝1且o＝2；因此，该第一光栅区162又被称为第一阶光栅结构区、且该第二光栅区163又被称为第二阶光栅结构区，藉以在该光栅层16形成一混合光栅结构；其中，该激光是由该第二光栅区163所定义的该出光面21垂直向上射出。In this embodiment, the grating layer 16 of the present invention is located in the upper cladding layer 17 of the semiconductor stack structure, and the grating layer 16 has a plurality of micro-grating structures arranged along at least a first horizontal direction. The grating layer 16 is divided at least in the first horizontal direction to include: at least one first grating area 162 and at least one second grating area 163, in each of the first grating area 162 and the second grating area 163 respectively It includes multiple micro-grating structures. Wherein, the grating periods of the plurality of micro-grating structures in the first grating region 162 conform to the following mathematical formula:

Moreover, the grating periods of the plurality of micro-grating structures in the second grating region 163 conform to the following mathematical formula: />

Among them, ∧ is the grating period length, λ is the laser wavelength of the laser, n _eff is the equivalent refractive index of the semiconductor waveguide, m and o are both positive integers, m and o are not equal, and o is an even multiple of m. Wherein, the light emitting surface 21 is defined by the second grating area 163 . In the first embodiment, m=1 and o=2; therefore, the first grating area 162 is also called a first-order grating structure area, and the second grating area 163 is also called a second-order grating structure region, so as to form a hybrid grating structure in the grating layer 16; wherein, the laser light is emitted vertically upward from the light-emitting surface 21 defined by the second grating region 163 .

In this embodiment, the grating layer 16 further includes a phase difference grating structure 164 . The phase difference grating structure 164 is located near the middle of the second grating region 163 in the first horizontal direction, and the width of the phase difference grating structure 164 can provide a phase difference distance, so that in the first horizontal direction There is a phase difference between the multiple micro-grating structures located on both sides of the phase difference grating structure 164; the phase difference distance provided by the phase difference grating structure 164 is a quarter of the laser wavelength (that is, λ /4-Shift). By arranging a λ/4-Shift phase difference grating structure in the center of the second-order grating structure region, the laser field of the laser element of the present invention can be modal stabilized and the optical coupling efficiency can be improved. Moreover, the number of the second grating area 163 is one and is located in a middle area of the grating layer 16 in the first horizontal direction, so that the first grating area 162 is substantially the second grating area located in the middle 163 is divided into left and right parts in the first horizontal direction. Wherein, the width of the second grating area 163 in the first horizontal direction is between one-sixth to one-half of the total width of the grating layer 16; the first grating area 162 is separated by the left, The width of the two right parts is roughly equal. Thus, the surface-emitting laser device of the present invention integrates the first-level and second-level grating structures in the same grating layer 16 . The low-loss first-order grating structure design is used to serve as a high-efficiency reflection feedback (feedback) area placed on the laser end face, and the second-order grating structure design is used only in the light-emitting area near the middle laser surface. In this way, it is possible to achieve the desired value between the pursuit of high slope efficiency (meaning a larger second-order grating structure area) and low critical current value Ith (meaning a smaller second-order grating structure area) balance.

以及σ²＝K²-δ²。其中：λ、n_eff、∧、i分别是激光波长、模态等效折射率、光栅周期、i多个；K为耦合常数与结构中光场与光栅耦合相关；A(或称R)与B(或称S)为向右向左前进的电场强度。若以图3A至图3C所示本发明第一实施例的激光元件来进行模拟，计算的条件及结果如下：Taking the typical edge-firing DFB laser element as shown in Figure 4 as an example, the method of transfer matrix (TransferMatrix) is adopted (reference books: semiconductor laser technology, written by Lu Tingchang and Wang Xingzong, Wunan Publishing House), and its related mathematical formula include:

And σ ² =K ² −δ ² . Among them: λ, n _eff , ∧, i are laser wavelength, modal equivalent refractive index, grating period, and multiple i; K is the coupling constant related to the coupling between the light field and the grating in the structure; A (or called R) and B (or called S) is the electric field strength going from right to left. If the simulation is performed with the laser element of the first embodiment of the present invention shown in FIGS. 3A to 3C , the calculation conditions and results are as follows:

The total length of the laser element L=L1+L2=250 μm. Wherein, L is the total length of the laser element in the first horizontal direction, L2 is the length of the second-level grating structure area in the middle, and L1 is the sum of the lengths of the two first-level grating structure areas located on the left and right sides of L2. The simulations were carried out with four structural changes of L2 length changes from 0 μm, 50 μm, 100 μm to 150 μm. The coupling constant (coupling constant) K1 of the first-order grating structure region is 12 cm ^-1 , and the coupling constant (coupling constant) K2 of the second-order grating structure region is 5 cm ^-1 . The front and rear end faces of the laser element are designed for Anti-Reflection (AR for short), and the reflectance is 0.1%. The simulated intensity distribution curves of the laser-guided mode along the ridge are shown in Figure 5A to Figure 5D (R ² ->(right propagation)+S ² <-(left propagation)); where, in the graph, X The axis is L (Longitudinal Normalized Position), and the Y axis is |E| ² (arbitrary unit Arb.Unit); L2 is the length of the second-order grating structure area. The relationship curves of normalized gain (g*L) and detuning relationship (δL) obtained by simulation are shown in FIGS. 6A to 6D . The relationship curve between the threshold gain (Threshold gain) obtained by simulation and different L2 lengths is shown in FIG. 7 . It can be known from the aforementioned Figures 5A to 5D, Figures 6A to 6D, and Figure 7 that the larger the L2 area (second-order grating structure area), the higher the light extraction efficiency, and it can be seen from Figure 7 that when the L2 area (second-order grating structure area) The larger the grating structure area), the higher the Ith (critical current). Therefore, with the above design, a trade-off can be made between low critical value and high output power, and then the desired value can be achieved by adjusting the appropriate length ratio of the L2 region (second-order grating structure region), such as but not limited to : When the width L2 of the L2 region (second-order grating structure region) in the first horizontal direction is between 1/6 to 1/2 of the total width L of the grating layer, it can be obtained at a high slope efficiency (slope The best balance between efficiency) and low critical current value Ith, which is difficult to achieve in the conventional technology (DFB laser element with pure second-order grating structure).

The same concept can be converted from a one-dimensional grating structure to a two-dimensional photonic crystal surface emitting laser (PCSEL for short). The first-order photonic crystals are deployed around the laser element, and the second-order photonic crystals are only deployed in the middle of the light output, and a phase difference structure is properly introduced to operate the mode. It is also possible to deploy several light outlets at the same time (that is, only deploy the second-order photonic crystals at the light outlets) to achieve an effect similar to that of a 2D array phase lock with multiple light sources.

Since in other embodiments of the present invention described below, the structures or functions of most of the components are the same or similar to those of the foregoing embodiments, the same or similar components will be directly given the same names and numbers, and the details will not be repeated. .

Please refer to FIG. 8 and FIG. 9 , which are a three-dimensional schematic view and a top view schematic view of a grating layer, respectively, of a second embodiment of a surface-emitting laser device of the present invention. In the second embodiment, the surface-emitting laser device may be a surface-emitting DFB laser device or a photonic crystal surface-emitting laser device (PCSEL), which generally includes a semiconductor stack structure and a grating layer on the semiconductor stack structure. 16 (or photonic crystal layer). The semiconductor stack structure can generate laser light with a laser wavelength λ when receiving a predetermined current, and the laser light is emitted vertically upward from a light-emitting surface 21 on the top surface of the semiconductor stack structure. The semiconductor stack structure includes from bottom to top: a semiconductor substrate 10, a lower cladding layer 11, a lower optical confinement layer (SCH) 12, an active layer 13, an upper optical confinement layer 14, the grating layer 16 (or photonic crystal layer), an upper cladding layer 17, a contact layer (not shown in this figure), and a metal layer (not shown in this figure), etc.

并且，该第二光栅(或光子晶体)区163内的多个该微光栅(或微光子晶体)结构的光栅(或光子晶体)周期是符合以下数学式：/>

其中，∧是光栅(或光子晶体)周期长度，λ是该激光的该激光波长，n_eff是半导体波导的等效折射率，m＝1且o＝2。因此，该第一光栅(或光子晶体)区162又被称为第一阶光栅(或光子晶体)结构区、且该第二光栅(或光子晶体)区163又被称为第二阶光栅(或光子晶体)结构区，藉以在该光栅层16(或光子晶体层)形成一混合光栅结构(或混合光子晶体结构)。其中，该激光是由该第二光栅(或光子晶体)区163所定义的出光面21垂直向上射出。藉此，当由垂直于该半导体堆叠结构的该顶面方向俯视观之(如图9所示)，该多个该微光栅(或微光子晶体)结构在该光栅(或光子晶体)层16上是呈现点状阵列排列，且由该第一水平方向上的该第二光栅(或光子晶体)区163及该第二水平方向上的该第二光栅(或光子晶体)区163两者协同定义出一矩形的至少一该出光面21。In this embodiment, the grating layer 16 (or photonic crystal layer) not only has a plurality of micro-grating (or photonic crystal) structures distributed and arranged along at least one first horizontal direction, and the grating layer 16 (or photonic crystal layer) layer) also has a plurality of micro-grating (or photonic crystal) structures along a second horizontal direction. The second horizontal direction is perpendicular to the first horizontal direction, and both the second horizontal direction and the first horizontal direction are perpendicular to the emitting direction of the laser light. The grating layer 16 (or photonic crystal layer) is divided in the first horizontal direction to include: at least one first grating (or photonic crystal) region 162 and at least one second grating (or photonic crystal) region 163, in each The first grating (or photonic crystal) region 162 and the second grating (or photonic crystal) region 163 respectively contain a plurality of micro grating (or photonic crystal) structures. Moreover, the grating layer 16 (or photonic crystal layer) is also divided in the second horizontal direction to include: at least one first grating (or photonic crystal) region 162 and at least one second grating (or photonic crystal) region 163 , each of the first grating (or photonic crystal) region 162 and the second grating (or photonic crystal) region 163 also respectively includes a plurality of the micro grating (or photonic crystal) structures. Wherein, no matter in the first horizontal direction or in the second horizontal direction, the grating (or photonic crystal) periods of the multiple micro-grating (or photonic crystal) structures in the first grating (or photonic crystal) region 162 are in accordance with the following mathematical formula:

And, the grating (or photonic crystal) periods of the plurality of micro-grating (or micro-photonic crystal) structures in the second grating (or photonic crystal) region 163 conform to the following mathematical formula: />

Wherein, Λ is the period length of the grating (or photonic crystal), λ is the laser wavelength of the laser, n _eff is the equivalent refractive index of the semiconductor waveguide, m=1 and o=2. Therefore, the first grating (or photonic crystal) region 162 is also called a first-order grating (or photonic crystal) structure region, and the second grating (or photonic crystal) region 163 is also called a second-order grating ( or photonic crystal) structure region, so as to form a hybrid grating structure (or photonic crystal structure) in the grating layer 16 (or photonic crystal layer). Wherein, the laser light is emitted vertically upward from the light emitting surface 21 defined by the second grating (or photonic crystal) region 163 . Thereby, when viewed from the direction perpendicular to the top surface of the semiconductor stack structure (as shown in FIG. 9 ), the plurality of micro-grating (or micro-photonic crystal) structures on the grating (or photonic crystal) layer 16 The above is arranged in a dotted array, and is coordinated by the second grating (or photonic crystal) region 163 on the first horizontal direction and the second grating (or photonic crystal) region 163 on the second horizontal direction At least one light emitting surface 21 of a rectangle is defined.

In addition, in this embodiment, the second grating (or photonic crystal) region 163 is located in a middle region of the grating (or photonic crystal) layer 16 between the first horizontal direction and the second horizontal direction. In other words, when viewed from a direction perpendicular to the top surface of the semiconductor stack structure, the second grating (or photonic crystal) region 163 is located in a central region of the top surface of the semiconductor stack structure, and the The first grating (or photonic crystal) region 162 substantially surrounds the outer peripheral region of the second grating (or photonic crystal) region 163 . Wherein, the widths of the second grating (or photonic crystal) region 163 in the first horizontal direction and the second horizontal direction are respectively between one-sixth and one-half of the grating (or photonic crystal) The total width of layer 16 in the first horizontal direction and in the second horizontal direction.

Please refer to FIG. 10 , which is a schematic top view of the grating (or photonic crystal) layer of the third embodiment of the surface-emitting laser element with the hybrid grating (or photonic crystal) structure of the present invention. Most of the structure of the laser element of the third embodiment is the same as that of the second embodiment shown in Fig. 8 and Fig. 9, the only difference is that in the third embodiment shown in Fig. 10, the grating ( or photonic crystal) layer contains two phase difference grating (or photonic crystal) structures 164 . One of the phase difference grating (or photonic crystal) structures 164 is located near the middle of the first horizontal direction in the second grating (or photonic crystal) region 163, and the other phase difference grating (or photonic crystal) The structure 164 is located near the middle of the second grating (or photonic crystal) region 163 in the second horizontal direction. The width of the phase difference grating (or photonic crystal) structure 164 can provide a phase difference distance, so that the two sides of the phase difference grating (or photonic crystal) structure 164 are respectively located in the first horizontal direction and the second horizontal direction. There is a phase difference between the multiple micro-grating (or micro-photonic crystal) structures. In this embodiment, the phase difference distance provided by the phase difference grating (or photonic crystal) structure 164 is a quarter of the laser wavelength.

Please refer to FIG. 11 , which is a schematic plan view of the grating layer of the fourth embodiment of the surface-emitting laser device with a hybrid grating (or photonic crystal) structure according to the present invention. Most of the structure of the laser element of the fourth embodiment is the same as that of the second embodiment shown in FIG. 8 and FIG. 9. The only difference is that in the fourth embodiment shown in FIG. The top surface of the structure includes a plurality of independently existing light-emitting surfaces 21 arranged in an array, and the grating (or photonic crystal) layer is located on each of the light-emitting surfaces 21 whether in the first horizontal direction or the second horizontal direction The second grating (or photonic crystal) region 163 is set in the direction, and the other regions of the grating (or photonic crystal) layer except for the plurality of light-emitting surfaces 21 are in the first horizontal direction or the second The first grating (or photonic crystal) region 162 is arranged in the horizontal direction; by this, a plurality of small light-emitting surfaces 21 that are independent and arranged in an array can be defined on the top surface of the semiconductor stack structure, so as to achieve similarity to most laser beams. The glow effect of an array of small light sources.

Please refer to FIG. 12A and FIG. 12B , which are schematic diagrams of the micro-grating structure of a traditional distributed feedback laser device with a pure first-order grating structure and a surface-emitting laser device with a first-order and second-order hybrid grating structure according to the present invention, respectively. As shown in FIG. 12B , the design feature of the surface-emitting laser device with the first-order and second-order hybrid grating structures of the present invention is that the regions 162 and 163 of the first-order grating structure and the second-order grating structure can be seamlessly integrated. together, and introduce a phase difference grating structure 164 in the middle light emitting area (light emitting surface 21 ). The integration method can start from the first-order grating structure, and remove the odd-numbered or even-numbered gratings in a specific area to form a second-order grating structure area with twice the period. The same concept can be developed on a two-dimensional photonic crystal surface emitting laser (PCSEL for short). The outer edge is the first-order photonic crystal (photonic crystal), which can freely arrange the second-order photons in the inner region. The light emitting position of the crystal.

Please refer to FIG. 13A to FIG. 13C , which are schematic diagrams of several steps in the manufacturing method of the surface-emitting laser device with a hybrid grating structure according to the present invention. A preferred embodiment of the manufacturing method of the surface-emitting laser device with a hybrid grating structure in the present invention may include the following steps:

Step (A): As shown in FIG. 13A, a semiconductor stack structure, a grating layer 16, and A protective layer. The semiconductor stack structure can generate a laser with a laser wavelength when receiving an electric current, and the laser light is emitted from a light-emitting surface of the semiconductor stack structure, and the light-emitting surface is located on a top surface of the semiconductor stack structure. The semiconductor stack structure includes from bottom to top: the semiconductor substrate 10 , a lower cladding layer 11 , a lower optical confinement layer 12 , an active layer 13 , an upper optical confinement layer 14 , and a spacer layer.

并且，该第二光栅区163内的多个该微光栅结构的光栅周期是符合以下数学式：/>

其中，∧是光栅周期长度，λ是该激光的该激光波长，n_eff是半导体波导的等效折射率，m和o都是正整数，m和o不相等，且o为m的偶数倍。其中，该出光面是由该第二光栅区163所定义。Step (B): As shown in FIG. 13B , process the grating layer 16 on the semiconductor stack junction by E-Beam Writer and NanoImprint to form a A plurality of micro-grating structures arranged in at least one first horizontal direction. Wherein, the grating layer is divided at least in the first horizontal direction into: at least one first grating area 162 located on both sides and at least one second grating area 163 located in the middle area, each of the first grating areas 162 And the second grating region 163 respectively includes a plurality of the micro grating structures. Moreover, a phase difference grating structure 164 is disposed near the center of the second grating region 163 . Wherein, the grating periods of the plurality of micro-grating structures in the first grating region 162 conform to the following mathematical formula:

Moreover, the grating periods of the plurality of micro-grating structures in the second grating region 163 conform to the following mathematical formula: />

Among them, ∧ is the grating period length, λ is the laser wavelength of the laser, n _eff is the equivalent refractive index of the semiconductor waveguide, m and o are both positive integers, m and o are not equal, and o is an even multiple of m. Wherein, the light emitting surface is defined by the second grating area 163 .

Step (C): As shown in FIG. 13C , an upper cladding layer 17 and a contact layer 18 are formed on the grating layer 16 by conventional semiconductor epitaxy process and photolithography process. above.

Please refer to FIG. 14 , which is a schematic perspective view of a fifth embodiment of the surface-emitting laser device of the present invention. Most of the structure of the laser element of the fifth embodiment is the same as that of the first embodiment shown in Figure 3A, the only difference is that in the fifth embodiment shown in Figure 14, the grating (or photonic crystal) layer 16 is located in the lower cladding layer 11 to form a p-side down surface emitting laser device.

However, the above-mentioned embodiments should not be used to limit the scope of application of the present invention. The scope of protection of the present invention should be based on the technical spirit defined in the content of the patent application of the present invention and the range included in equivalent changes. That is, all equivalent changes and modifications made according to the patent scope of the present invention will still not lose the gist of the present invention, nor depart from the spirit and scope of the present invention, so all should be regarded as further implementation status of the present invention.

Claims (9)

1. A surface-emitting laser element with a hybrid grating structure, which can produce laser light with a laser wavelength, is characterized in that the surface-emitting laser element comprises: A semiconductor stack structure, capable of generating the laser light with the laser wavelength when receiving an electric current, and causing the laser light to emit from a light-emitting surface of the semiconductor stack structure, and the light-emitting surface is located on a top surface of the semiconductor stack structure; A grating layer, located on the semiconductor stack structure, the grating layer has a plurality of micro-grating structures distributed and arranged along at least one first horizontal direction; Wherein, the grating layer is distinguished at least in the first horizontal direction to include: at least one first grating area and at least one second grating area, and each of the first grating area and the second grating area contains a plurality of The micro-grating structure; wherein, the grating period of the plurality of micro-grating structures in the first grating area is in accordance with the following mathematical formula:

In addition, the grating period of the plurality of micro-grating structures in the second grating area is in accordance with the following mathematical formula: />

Wherein, ∧ is the period length of the grating, λ is the laser wavelength of the laser, and n _eff is the equivalent refractive index of the semiconductor waveguide; wherein, m=1 and o=2; the first grating region is also called the first order The grating structure area, and the second grating area is also called the second-order grating structure area, so as to form a hybrid grating structure in the grating layer; wherein, the light-emitting surface is defined by the second grating area, and the laser is Emit vertically from the light-emitting surface; The grating layer also has a plurality of micro-grating structures along a second horizontal direction, the second horizontal direction is perpendicular to the first horizontal direction; the grating layer is also divided into at least one in the second horizontal direction The first grating area and at least one of the second grating areas respectively include a plurality of the micro grating structures in each of the first grating area and the second grating area in the second horizontal direction; Viewed in the direction of the top surface of the semiconductor stack structure, the plurality of micro-grating structures are arranged in a dot-like array on the grating layer, and the second grating region and the second grating in the first horizontal direction The second grating area in the horizontal direction cooperates to define the rectangular light-emitting surface; The grating layer further includes two phase difference grating structures; one of the phase difference grating structures is located near the middle of the second grating region in the first horizontal direction, and the other phase difference grating structure is Located near the middle in the second horizontal direction in the second grating area; and the width of the phase difference grating structure can provide a phase difference distance, so that the positions in the first horizontal direction and the second horizontal direction are respectively There is a phase difference between the multiple micro-grating structures on both sides of the phase difference grating structure; the phase difference distance provided by the phase difference grating structure is a quarter of the laser wavelength. 2. The surface-emitting laser device with a hybrid grating structure according to claim 1, wherein the second grating region is located in a middle region of the grating layer between the first horizontal direction and the second horizontal direction ; when viewed from the direction perpendicular to the top surface of the semiconductor stack structure, the second grating region is located in a central region of the top surface of the semiconductor stack structure, and the first grating region is substantially surrounding the position The outer peripheral area of the second grating area; wherein, the widths of the second grating area in the first horizontal direction and the second horizontal direction are respectively between one-sixth and one-half of the grating layer total width in the first horizontal direction and the second horizontal direction. 3. The surface-emitting laser device with a hybrid grating structure according to claim 1, wherein the top surface of the semiconductor stack structure includes a plurality of independent light-emitting surfaces arranged in an array, and the grating layer The second grating region is provided on each of the light-emitting surfaces no matter in the first horizontal direction or in the second horizontal direction, and other regions of the grating layer except a plurality of the light-emitting surfaces are located in the first horizontal direction or in the second horizontal direction. The first grating area is arranged in the first horizontal direction or the second horizontal direction; thereby, a plurality of independent small light-emitting surfaces arranged in an array can be defined on the top surface of the semiconductor stack structure. 4. The surface-emitting laser element with a hybrid grating structure according to claim 1, wherein the semiconductor stack structure comprises: a semiconductor substrate; A cladding layer (cladding layer) is located on the semiconductor substrate; A light confinement (Separated Confinement Hetero-Structure; SCH for short) layer is located on the lower cladding layer; an active region layer located on the lower optical confinement layer; a glazing-limited layer located on the active layer; A spacer layer is located on the glazing confinement layer; wherein, the grating layer is located on the spacer layer; an upper cladding layer is located on the grating layer; and A contact layer is located on the upper cladding layer. 5. A method for preparing a surface-emitting laser element with a hybrid grating structure, characterized in that it comprises the following steps: Step (A): A semiconductor stack structure is formed on a semiconductor substrate by a semiconductor epitaxy process; the semiconductor stack structure can generate a laser with a laser wavelength when receiving an electric current, and the laser light is emitted from the semiconductor stack A light-emitting surface of the structure is emitted, and the light-emitting surface is located on a top surface of the semiconductor stack structure; Step (B): forming a grating layer on the semiconductor stack structure by electron beam printing and nanoimprinting process, and is located on the semiconductor stack structure; the grating layer has a structure along at least one first horizontal direction A plurality of micro-grating structures arranged; Step (C): forming an upper cladding layer and a contact layer on the grating layer by semiconductor epitaxy process and photolithography process, and are located above the grating layer; Wherein, the grating layer is distinguished at least in the first horizontal direction to include: at least one first grating area and at least one second grating area, and each of the first grating area and the second grating area contains a plurality of The micro-grating structure; wherein, the grating period of the plurality of micro-grating structures in the first grating area is in accordance with the following mathematical formula:

In addition, the grating period of the plurality of micro-grating structures in the second grating area is in accordance with the following mathematical formula: />

Wherein, ∧ is the period length of the grating, λ is the laser wavelength of the laser, and n _eff is the equivalent refractive index of the semiconductor waveguide; wherein, m=1 and o=2; the first grating region is also called the first order The grating structure area, and the second grating area is also called the second-order grating structure area, so as to form a hybrid grating structure in the grating layer; Wherein, the light-emitting surface is defined by the second grating area, and the laser is emitted vertically from the light-emitting surface; The grating layer also has a plurality of micro-grating structures along a second horizontal direction, the second horizontal direction is perpendicular to the first horizontal direction; the grating layer is also divided into at least one in the second horizontal direction The first grating area and at least one of the second grating area respectively include a plurality of the micro-grating structures in each of the first grating area and the second grating area in the second horizontal direction; Viewed in the direction of the top surface of the semiconductor stack structure, the plurality of micro-grating structures are arranged in a dot-like array on the grating layer, and the second grating region and the second grating in the first horizontal direction The second grating area in the horizontal direction cooperates to define the rectangular light-emitting surface; The grating layer further includes two phase difference grating structures; one of the phase difference grating structures is located near the middle of the second grating region in the first horizontal direction, and the other phase difference grating structure is Located near the middle in the second horizontal direction in the second grating area; and the width of the phase difference grating structure can provide a phase difference distance, so that the positions in the first horizontal direction and the second horizontal direction are respectively There is a phase difference between the multiple micro-grating structures on both sides of the phase difference grating structure; the phase difference distance provided by the phase difference grating structure is a quarter of the laser wavelength. 6. The method for manufacturing a surface-emitting laser device with a hybrid grating structure according to claim 5, wherein the second grating region is located between the first horizontal direction and the second horizontal direction of the grating layer a middle region; when viewed from a direction perpendicular to the top surface of the semiconductor stack structure, the second grating region is located in a central region of the top surface of the semiconductor stack structure, and the first grating region is substantially is the outer peripheral area surrounding the second grating area; wherein, the widths of the second grating area in the first horizontal direction and in the second horizontal direction are respectively between one-sixth and one-half The total width of the grating layer in the first horizontal direction and the second horizontal direction. 7. The method for manufacturing a surface-emitting laser device with a hybrid grating structure according to claim 5, wherein the top surface of the semiconductor stack structure includes a plurality of independent light-emitting surfaces arranged in an array, The grating layer is provided with the second grating region on each of the light-emitting surfaces no matter in the first horizontal direction or the second horizontal direction, and the other regions of the grating layer except for a plurality of the light-emitting surfaces are The first grating region is arranged in the first horizontal direction or the second horizontal direction; thereby, a plurality of small light-emitting surfaces that are independent and arranged in an array can be defined on the top surface of the semiconductor stack structure. 8. A surface-emitting laser element that can produce laser light with a laser wavelength, characterized in that the surface-emitting laser element comprises: A semiconductor stack structure, capable of generating the laser light with the laser wavelength when receiving an electric current, and causing the laser light to emit from a light-emitting surface of the semiconductor stack structure, and the light-emitting surface is located on a top surface of the semiconductor stack structure; A photonic crystal layer located on the semiconductor stack structure, the photonic crystal layer has a plurality of micro-photonic crystal structures distributed and arranged along a first horizontal direction and a second horizontal direction, the second horizontal direction and the first horizontal direction The horizontal direction is vertical; wherein, the photonic crystal layer is divided in the first horizontal direction and the second horizontal direction to include: at least one first photonic crystal region and at least one second photonic crystal region, in each of the first The photonic crystal region and the second photonic crystal region respectively contain a plurality of the micro-photonic crystal structures; wherein, the plurality of the micro-photonic crystal structures in the first photonic crystal region are in the first horizontal direction and the second horizontal direction The period of the photonic crystal conforms to the following mathematical formula:

Moreover, the photonic crystal periods of the plurality of micro-photonic crystal structures in the second photonic crystal region in the first horizontal direction and the second horizontal direction all conform to the following mathematical formula: />

Wherein, ∧ is the photonic crystal period length, λ is the laser wavelength of the laser, and n _eff is the equivalent refractive index of the semiconductor waveguide; wherein, m=1 and o=2; Wherein, the light-emitting surface is defined by the second photonic crystal region, and the laser is emitted vertically from the light-emitting surface; When viewed from the direction perpendicular to the top surface of the semiconductor stack structure, a plurality of micro-photonic crystal structures are arranged in a dot-like array on the photonic crystal layer, and from the second photonic crystal in the first horizontal direction region and the second photonic crystal region in the second horizontal direction cooperate to define the rectangular light-emitting surface; The photonic crystal layer further includes two phase difference photonic crystal structures; one of the phase difference photonic crystal structures is located near the middle of the second photonic crystal region in the first horizontal direction, and the other phase difference photonic crystal structure The photonic crystal structure is located near the middle of the second photonic crystal region in the second horizontal direction; and the width of the phase difference photonic crystal structure can provide a phase difference distance, so that in the first horizontal direction and There is a phase difference between the multiple micro-photonic crystal structures located on both sides of the phase-difference photonic crystal structure in the second horizontal direction; the phase difference distance provided by the phase-difference photonic crystal structure is a quarter of the laser wavelength. 9. The surface-emitting laser element according to claim 8, wherein the top surface of the semiconductor stack structure includes a plurality of independent light-emitting surfaces arranged in an array, and the photonic crystal layer is on each of the Whether in the first horizontal direction or in the second horizontal direction, the light-emitting surface is provided with the second photonic crystal region, and the other regions of the photonic crystal layer except a plurality of the light-emitting surfaces are located in the first horizontal direction The first photonic crystal region is arranged in the horizontal direction or the second horizontal direction; thereby, a plurality of independent small light-emitting surfaces arranged in an array can be defined on the top surface of the semiconductor stack structure.

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