Preparation method of high-power quantum cascade laser

Abstract

The invention relates to the technical field of lasers, in particular to a preparation method of a high-power quantum cascade laser, and the method comprises the steps: forming a stacking structure which comprises a first part and second parts located at the two sides of the first part, the active layer, the upper waveguide layer, the upper cladding, the cover layer and the lower waveguide layer with partial thickness corresponding to the first part are used for forming a waveguide structure; patterning the stacked structure to form a waveguide structure; wherein before the waveguide structure is formed or after the waveguide structure is formed, a first mask layer with an injection window is formed on the surface, far away from the upper cladding layer, of the cover layer, the second part is exposed out of the injection window, and ion injection is carried out through the injection window, forming an insulating region within a partial thickness of the waveguide structure adjacent to the second portion and within a partial thickness of the second portion away from the substrate; and after the waveguide structure with the insulating region is formed, forming a first electrode layer on the insulating region. The preparation difficulty and the preparation cost of the high-power quantum cascade laser can be reduced at least.

Description

Technical Field

[0001] The invention belongs to the technical field of lasers, and in particular relates to a method for preparing a high-power quantum cascade laser. Background Art

[0002] Quantum cascade laser (QCL) is a semiconductor laser that achieves laser output based on inter-subband transitions. Its advent has created a new field of semiconductor lasers in the mid- and far-infrared and terahertz bands. It has been widely used in many fields such as industry, agriculture, medical treatment, environmental protection and national defense, and has become an important infrared laser light source in applications such as transmission and detection.

[0003] Quantum cascade lasers usually operate under high bias voltage and high current density. In addition, the thermal conductivity of the superlattice structure in the active area is extremely low, which makes it easy for a large amount of heat to be generated and accumulated inside the laser. If the waveguide structure is not designed properly, the heat cannot be dissipated in time, which will cause the temperature of the active area to rise rapidly, the threshold current density to increase, and the conversion efficiency and maximum output power to decrease. At present, due to the above limitations, the flipping current of quantum cascade lasers working continuously at room temperature can reach the ampere level.

[0004] Currently, there are two main strategies for reducing the temperature of the active area: one is to reduce heat generation, and the other is to enhance heat dissipation. Driving quantum cascade lasers with pulsed current is one of the important methods to reduce heat generation. Pulsed pump current can shorten the working time of the laser per unit time, thereby reducing heat accumulation. Methods to improve heat dissipation efficiency include: forming Fe-doped InP secondary epitaxy in the grooves on both sides of the ridge waveguide, electroplating gold on the top electrode, and using flip-chip packaging technology. The common goal of these technical means is to increase the contact area between the ridge waveguide structure and the high thermal conductivity material, increase the lateral heat dissipation capacity of the ridge waveguide structure, and thus dissipate the heat of the active area more efficiently.

[0005] Driving a quantum cascade laser with pulsed current can indeed significantly reduce heat generation, but because the laser operates in pulsed current mode, its average output power is much lower than the output power of the continuous mode under the same current conditions. InP doped with Fe in the grooves on both sides of the ridge waveguide is an effective means of improving heat dissipation. 2 (SiO 2The thermal conductivity of InP doped with Fe is about 1.4W / m·K) or silicon nitride (the thermal conductivity of silicon nitride is about 50W / m·K). InP doped with Fe has a thermal conductivity of up to about 68W / m·K. Studies have shown that the maximum continuous output power of quantum cascade lasers prepared by this technology can be increased by about three times at room temperature. However, this technology has the problem of high time and economic costs, and cost factors need to be comprehensively considered when applying it. Electroplating gold and flip-chip packaging processes have become common methods in the preparation of quantum cascade lasers, especially in the manufacture of high-power lasers. Improving the output power is almost inseparable from the support of these two processes.

[0006] The overheating problem of the active area of ​​quantum cascade lasers is the main bottleneck limiting their maximum output power. Therefore, improving heat dissipation capabilities to further increase output power is crucial to their future development. Summary of the invention

[0007] In view of this, the present invention aims to provide a method for preparing a high-power quantum cascade laser, which can significantly improve the heat dissipation capacity of the quantum cascade laser and has a relatively simple process, thereby maximizing the maximum output power of the laser.

[0008] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0009] The invention provides a method for preparing a high-power quantum cascade laser, comprising: forming a substrate, a buffer layer, a lower waveguide layer, an active layer, an upper waveguide layer, an upper cladding layer and a cap layer stacked in sequence along a first direction to form a stacked structure, wherein the stacked structure comprises a first part and a second part located on both sides of the first part, wherein the active layer, the upper waveguide layer, the upper cladding layer, the cap layer and the lower waveguide layer of a partial thickness corresponding to the first part are used to form a waveguide structure; patterning the stacked structure, removing the second part of a partial thickness to form a waveguide structure; wherein before or after the waveguide structure is formed, forming a first mask layer having an injection window on a surface of the cap layer away from the upper cladding layer, wherein the injection window exposes the second part, and ion implantation is performed through the injection window to form an insulating region in the waveguide structure of a partial thickness adjacent to the second part and in the second part of a partial thickness away from the substrate; after the waveguide structure having the insulating region is formed, forming a first electrode layer on the insulating region and on the top surface of the waveguide structure.

[0010] Furthermore, the implanted ions in the ion implantation step include at least one of hydrogen ions, helium ions, nitrogen ions or argon ions.

[0011] Furthermore, the step of forming an insulating region before forming a waveguide structure includes: forming a first mask layer on the top surface of the stacked structure, an injection window exposing the second portion, and performing ion implantation through the injection window, wherein an implantation depth of the ion implantation along a first direction is greater than a total thickness of the active layer, the upper waveguide layer, the upper cladding layer, and the cap layer, and an implantation depth of the ion implantation is less than a total thickness of the lower waveguide layer, the active layer, the upper waveguide layer, the upper cladding layer, and the cap layer.

[0012] Furthermore, the implantation direction of the ion implantation is a first direction.

[0013] Furthermore, the step of forming an insulating area after forming the waveguide structure includes: forming a first mask layer on the top surface of the waveguide structure, the first mask layer exposing the remaining second part and the side of the waveguide structure, and the ion implantation includes a first implantation process in a first implantation direction and a second implantation process in a second implantation direction, the angle between the first implantation direction and the second implantation direction is 90°, and the angle between the first implantation direction and the first direction is 45°, and the angle between the second implantation direction and the first direction is 45°.

[0014] Furthermore, the thickness of the insulating region in the waveguide structure is in the range of 0.9 μm to 1.1 μm.

[0015] Furthermore, the step of patterning the stacked structure to form a waveguide structure before forming the insulating region includes: forming a second mask layer having an etching window on the first portion, the etching window exposing the top surface of the second portion, and removing the cap layer, the upper cladding layer, the upper waveguide layer, the active layer and a partial thickness of the lower waveguide layer located in the second portion through the etching window to form a waveguide structure.

[0016] Furthermore, the first mask layer is a dielectric layer, and the step of forming the first mask layer after forming the waveguide structure includes: the second mask layer is a photoresist layer, removing the second mask layer, forming an initial first mask layer on the top surface of the remaining second part and the surface of the waveguide structure, and then removing the initial first mask layer on the side of the waveguide structure and the second part, and the remaining initial first mask layer serves as the first mask layer; or, the second mask layer is a dielectric layer, and the second mask layer serves as the first mask layer.

[0017] Furthermore, after forming the insulating region, the step of patterning the stacked structure to form a waveguide structure includes: removing the first mask layer, forming a photoresist layer on the top surface of the first portion, the photoresist layer having an etching window exposing the second portion, removing the cap layer, the upper cladding layer, the upper waveguide layer, the active layer and a partial thickness of the lower waveguide layer located in the second portion through the etching window to form the waveguide structure, and then removing the photoresist layer; or forming a photoresist layer on the top surface of the first mask layer, the photoresist layer having an etching window exposing the second portion, removing the cap layer, the upper cladding layer, the upper waveguide layer, the active layer and a partial thickness of the lower waveguide layer located in the second portion through the etching window to form the waveguide structure, and then removing the photoresist layer and the first mask layer.

[0018] Furthermore, the energy of the ion implantation is in the range of 50keV to 500keV, and the implantation dose of the ion implantation is 2E12cm -2 ~5E15cm -2 within the range.

[0019] Compared with the prior art, the invention can achieve the following beneficial effects: the preparation method of the high-power quantum cascade laser provided by the invention processes the ridge waveguide of the semiconductor laser by means of ion implantation, so that the surface of the laser, except for the top of the ridge waveguide structure, is electrically insulated. Specifically, the characteristic of ion implantation that reduces the carrier mobility of the semiconductor material is used to form an insulating region, thereby forming a surface structure similar to the ridge waveguide of the traditional quantum cascade laser, but without growing an electrical insulating film, an insulating region is formed in the semiconductor material by ion implantation. Since the method does not use a dielectric film to achieve electrical insulation, but instead achieves electrical insulation through the material body after ion implantation, the waveguide structure can be directly in contact with the first electrode layer, and the first electrode layer is usually a metal with high thermal conductivity such as gold (the thermal conductivity of gold is 320 W / m·K), thereby avoiding the influence of the formation of a dielectric film on heat dissipation, significantly enhancing the heat dissipation capacity of the waveguide structure, thereby greatly improving the overall performance of the device, especially its maximum output power. In addition, compared with the method of forming a secondary epitaxy (Fe-doped InP), the preparation method of the high-power quantum cascade laser provided by the present invention can achieve a heat dissipation effect close to or even higher than that of the same, while significantly reducing the process complexity and process cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0021] Figure 1 A schematic diagram of the structure of a high-power quantum cascade laser according to an embodiment of the present invention;

[0022] Figure 2 A schematic flow chart of a first method of preparing a high-power quantum cascade laser according to an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of each step of a method for preparing a high-power quantum cascade laser according to an embodiment of the present invention;

[0024] Figure 4 The present invention is a schematic flow chart of a second method for preparing a high-power quantum cascade laser according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0027] In the description of the invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0028] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0030] The invention provides a method for preparing a high-power quantum cascade laser. Figure 1 The high-power quantum cascade laser and the preparation method of the high-power quantum cascade laser include: forming a substrate 9, a buffer layer 8, a lower waveguide layer 7, an active layer 5, an upper waveguide layer 4, an upper cladding layer 3 and a cap layer 2 stacked in sequence along a first direction X to form a stacked structure, the stacked structure includes a first part I and a second part II located on both sides of the first part I, the active layer 5, the upper waveguide layer 4, the upper cladding layer 3, the cap layer 2 and the lower waveguide layer 7 of partial thickness corresponding to the first part I are used to form a waveguide structure; patterning the stacked structure, removing a portion of the thickness The second part II is formed to form a waveguide structure; wherein, before or after the waveguide structure is formed, a first mask layer 14 having an injection window is formed on the surface of the cover layer 2 away from the upper cladding layer 3, the injection window exposes the second part II, and ion implantation is performed through the injection window to form an insulating region 6 in the partial thickness of the waveguide structure adjacent to the second part II and in the partial thickness of the second part II away from the substrate 9; after the waveguide structure having the insulating region 6 is formed, a first electrode layer 1 is formed on the insulating region 6 and on the top surface of the waveguide structure.

[0031] It should be noted that the concentration and depth of the implanted ions can be effectively controlled by precisely controlling the energy, beam density, annealing temperature and time of the ion implantation, thereby minimizing the damage that the ion implantation may cause to the various layers of materials.

[0032] Furthermore, the implanted ions in the ion implantation step include at least one of hydrogen ions, helium ions, nitrogen ions or argon ions, preferably hydrogen ions.

[0033] The present invention provides a method for preparing a high-power quantum cascade laser, which includes two methods. Figure 2 The first method is to form an insulating region 6 before forming a waveguide structure, referring to Figure 3 and Figure 4 The second method is to form the insulating region 6 after forming the waveguide structure. The two methods are described in detail below.

[0034] For the first method, it is first necessary to form a substrate 9, a buffer layer 8, a lower waveguide layer 7, an active layer 5, an upper waveguide layer 4, an upper cladding layer 3 and a cap layer 2 stacked in sequence along a first direction X to form a stacked structure, the stacked structure comprising a first portion I and a second portion II located on both sides of the first portion I, the active layer 5, the upper waveguide layer 4, the upper cladding layer 3, the cap layer 2 and a lower waveguide layer 7 of a partial thickness corresponding to the first portion I are used to form a waveguide structure. Further, the step of forming an insulating region 6 before forming the waveguide structure comprises: forming a first mask layer 14 on the top surface of the stacked structure, an injection window exposing the second portion II, performing ion implantation through the injection window, and along the first direction X, the implantation depth of the ion implantation is greater than the total thickness of the active layer 5, the upper waveguide layer 4, the upper cladding layer 3 and the cap layer 2, and the implantation depth of the ion implantation is less than the total thickness of the lower waveguide layer 7, the active layer 5, the upper waveguide layer 4, the upper cladding layer 3 and the cap layer 2.

[0035] Furthermore, the implantation direction of the ion implantation is the first direction X.

[0036] Furthermore, after forming the insulating region 6, the step of patterning the stacked structure to form a waveguide structure includes: removing the first mask layer 14, forming a photoresist layer on the top surface of the first part I, the photoresist layer having an etching window exposing the second part II, removing the cap layer 2, the upper cladding layer 3, the upper waveguide layer 4, the active layer 5 and a partial thickness of the lower waveguide layer 7 located in the second part II through the etching window to form a waveguide structure, and then removing the photoresist layer; or, forming a photoresist layer on the top surface of the first mask layer 14, the photoresist layer having an etching window exposing the second part II, removing the cap layer 2, the upper cladding layer 3, the upper waveguide layer 4, the active layer 5 and a partial thickness of the lower waveguide layer 7 located in the second part II through the etching window to form a waveguide structure, and then removing the photoresist layer and the first mask layer 14.

[0037] In some examples, a 2 μm thick silicon oxide layer is deposited on the top surface of the stacked structure (the surface of the cap layer 2 away from the upper cladding layer 3) using a plasma chemical vapor deposition process. After the silicon oxide layer is grown, a pattern for ion implantation is formed on the silicon oxide layer by a photolithography process, i.e., a first mask layer 14 is formed. Then, ion implantation is performed on the stacked structure. The implantation energy of the ion implantation can be 100 keV, the type of implanted ions can be hydrogen ions, the implantation angle is 0° (the corresponding implantation direction is the first direction X), and the depth of the ion implantation must pass through the active layer 5. Subsequently, a photolithography process is performed again to etch the stacked structure to form a waveguide structure. Finally, the first electrode layer 1 is grown, and after the substrate 9 is thinned, the second electrode layer 10 is grown on the back of the substrate 9.

[0038] For the second method, refer to Figure 3 and Figure 4First, it is necessary to form a substrate 9, a buffer layer 8, a lower waveguide layer 7, an active layer 5, an upper waveguide layer 4, an upper cladding layer 3 and a cover layer 2 which are stacked in sequence along a first direction X to form a stacked structure. The stacked structure includes a first part I and a second part II located on both sides of the first part I. The active layer 5, the upper waveguide layer 4, the upper cladding layer 3, the cover layer 2 and the lower waveguide layer 7 with a partial thickness corresponding to the first part I are used to form a waveguide structure.

[0039] Further, the step of patterning the stacked structure to form a waveguide structure before forming the insulating region 6 includes: referring to Figure 3 A second mask layer 11 having an etching window is formed on the first part I, the etching window exposes the top surface of the second part II, and the cap layer 2, the upper cladding layer 3, the upper waveguide layer 4, the active layer 5 and a partial thickness of the lower waveguide layer 7 located in the second part II are removed through the etching window to form a waveguide structure.

[0040] Furthermore, the step of forming the insulating region 6 after forming the waveguide structure includes: forming a first mask layer 14 on the top surface of the waveguide structure, the first mask layer 14 exposing the remaining second part II and the side of the waveguide structure, and the ion implantation includes a first implantation process in a first implantation direction and a second implantation process in a second implantation direction, the angle between the first implantation direction and the second implantation direction is 90°, and the angle between the first implantation direction and the first direction X is 45°, and the angle between the second implantation direction and the first direction X is 45°.

[0041] Furthermore, the thickness of the insulating region 6 in the waveguide structure is in the range of 0.9 μm to 1.1 μm.

[0042] Furthermore, the first mask layer 14 is a dielectric layer, and the steps of forming the first mask layer 14 after forming the waveguide structure include: referring to Figure 3 The second mask layer 11 is a photoresist layer. The second mask layer 11 is removed, and an initial first mask layer 12 is formed on the top surface of the remaining second part II and the surface of the waveguide structure. The initial first mask layer 12 on the side surface of the waveguide structure and the second part II is then removed, and the remaining initial first mask layer 12 is used as the first mask layer 14.

[0043] In some other embodiments, the first mask layer 14 is a silicon oxide layer, the second mask layer 11 is a dielectric layer, and the step of forming the first mask layer 14 after forming the waveguide structure includes: using the second mask layer 11 as the first mask layer 14 .

[0044] In some embodiments, the dielectric layer is a silicon oxide layer or a silicon nitride layer.

[0045] In some examples, the thickness of the initial first mask layer 12 is 2 μm, and the initial first mask layer 12 can be grown by a plasma enhanced chemical vapor deposition process. After the initial first mask layer 12 is grown, the initial first mask layer 12 is etched by a photolithography process to form a pattern for ion implantation. Subsequently, ion implantation is performed, the implantation energy can be 100 keV, the implanted ion type can be hydrogen ions, the implantation depth can be about 1 μm, the number of implantations is twice, and the two sides of the waveguide structure are respectively implanted at an angle of 45°, thereby forming an insulating region 6. After the insulating region 6 is formed, except for the top of the waveguide structure, the remaining areas are insulated. Finally, the growth of the first electrode layer 1 is completed, and the second electrode layer 10 is grown on the back of the substrate 9 after thinning.

[0046] For the above two methods, in some embodiments, the energy of ion implantation is in the range of 50keV to 500keV, and the implantation dose of ion implantation is in the range of 2E12cm -2 ~5E15cm -2 within the range.

[0047] For the above two methods, in some examples, the thickness of the first electrode layer 1 is 300nm, and the material of the first electrode layer 1 includes gold; in some examples, the material of the cap layer 2 is N-type InP, and the thickness of the cap layer 2 is 200nm; in some examples, the material of the upper cladding layer 3 is N-type InP, and the thickness of the upper cladding layer 3 is 1.5μm; in some examples, the material of the upper waveguide layer 4 is N-type InP, and the thickness of the upper waveguide layer 4 is 1.5μm; in some examples, the thickness of the active layer 5 is 200nm, and the active layer may include a barrier layer and 40 layers of lattice-matched and periodically arranged In 0.53 Ga 0.47 As and In 0.52 Al 0.48 As; in some examples, the thickness of the insulating region 6 is 1 μm; in some examples, the material of the lower waveguide layer 7 includes N-type InP, and the thickness of the lower waveguide layer 7 is 5 μm; in some examples, the buffer layer 8 is a 1.5 μm thick N-type InP layer; in some examples, the substrate 9 is an N-type InP layer; in some examples, the thickness of the second electrode layer 10 is 300 nm.

[0048] The present invention uses the material body of the waveguide structure for electrical insulation, and does not require additional growth of an electrical insulation film, thereby avoiding the short circuit problem that may be caused by the side wall not being completely covered with the electrical insulation layer or the electrical insulation layer being too thin, and at the same time eliminating the additional electrical insulation layer photolithography etching step, thereby simplifying the process flow and improving the stability of the device; since no electrical insulation layer is required, the material body of the waveguide structure can directly contact the metal electrode with ultra-high thermal conductivity, greatly improving the heat dissipation capacity of the quantum cascade laser waveguide structure; the significant improvement in heat dissipation capacity enables the quantum cascade laser prepared by the method to achieve a maximum output power several times higher than that of a traditional dielectric film insulation laser under room temperature continuous current working conditions, and in addition, the process flow is less difficult to implement, but the improvement effect of heat dissipation capacity is extremely significant.

[0049] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0050] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-power quantum cascade laser, characterized in that: include: A substrate, a buffer layer, a lower waveguide layer, an active layer, an upper waveguide layer, an upper cladding layer and a cap layer are sequentially stacked along a first direction to form a stacked structure, wherein the stacked structure includes a first portion and a second portion located on both sides of the first portion, wherein the active layer, the upper waveguide layer, the upper cladding layer, the cap layer and a partial thickness of the lower waveguide layer corresponding to the first portion are used to form a waveguide structure; Patterning the stacked structure to remove a portion of the thickness of the second portion to form the waveguide structure; Wherein, before or after forming the waveguide structure, a first mask layer having an injection window is formed on a surface of the cap layer away from the upper cladding layer, the injection window exposes the second portion, and ion implantation is performed through the injection window to form an insulating region in a portion of the thickness of the waveguide structure adjacent to the second portion and in a portion of the thickness of the second portion away from the substrate; After forming the waveguide structure with the insulating region, a first electrode layer is formed on the insulating region and the top surface of the waveguide structure.

2. The method for preparing a high-power quantum cascade laser according to claim 1, characterized in that: The implanted ions in the ion implantation step include at least one of hydrogen ions, helium ions, nitrogen ions or argon ions.

3. The method for preparing a high-power quantum cascade laser according to claim 1 or 2, characterized in that: The step of forming the insulating region before forming the waveguide structure comprises: The first mask layer is formed on the top surface of the stacked structure, the injection window exposes the second part, and ion injection is performed through the injection window. Along the first direction, the injection depth of the ion injection is greater than the total thickness of the active layer, the upper waveguide layer, the upper cladding layer and the cap layer, and the injection depth of the ion injection is less than the total thickness of the lower waveguide layer, the active layer, the upper waveguide layer, the upper cladding layer and the cap layer.

4. The method for preparing a high-power quantum cascade laser according to claim 3, characterized in that: The implantation direction of the ion implantation is the first direction.

5. The method for preparing a high-power quantum cascade laser according to claim 1 or 2, characterized in that: The step of forming the insulating region after forming the waveguide structure includes: forming a first mask layer on the top surface of the waveguide structure, the first mask layer exposing the remaining second portion and the side surface of the waveguide structure, the ion implantation includes a first implantation process in a first implantation direction and a second implantation process in a second implantation direction, the angle between the first implantation direction and the second implantation direction is 90°, the angle between the first implantation direction and the first direction is 45°, and the angle between the second implantation direction and the first direction is 45°.

6. The method for preparing a high-power quantum cascade laser according to claim 1, characterized in that: The thickness of the insulating region in the waveguide structure is in the range of 0.9 μm to 1.1 μm.

7. The method for preparing a high-power quantum cascade laser according to claim 1, characterized in that: The step of patterning the stacked structure to form the waveguide structure before forming the insulating region comprises: A second mask layer having an etching window is formed on the first portion, wherein the etching window exposes a top surface of the second portion, and the cap layer, the upper cladding layer, the upper waveguide layer, the active layer and a partial thickness of the lower waveguide layer located in the second portion are removed through the etching window to form the waveguide structure.

8. The method for preparing a high-power quantum cascade laser according to claim 7, characterized in that: The first mask layer is a dielectric layer, and the step of forming the first mask layer after forming the waveguide structure includes: The second mask layer is a photoresist layer, the second mask layer is removed, an initial first mask layer is formed on the remaining top surface of the second portion and the surface of the waveguide structure, and then the initial first mask layer on the side surface of the waveguide structure and the second portion is removed, and the remaining initial first mask layer serves as the first mask layer; Alternatively, the second mask layer is a dielectric layer, and the second mask layer is used as the first mask layer.

9. The method for preparing a high-power quantum cascade laser according to claim 1, characterized in that: The step of patterning the stacked structure to form the waveguide structure after forming the insulating region comprises: removing the first mask layer, forming a photoresist layer on the top surface of the first portion, wherein the photoresist layer has an etching window exposing the second portion, removing the cap layer, the upper cladding layer, the upper waveguide layer, the active layer and a partial thickness of the lower waveguide layer located in the second portion through the etching window to form the waveguide structure, and then removing the photoresist layer; Alternatively, a photoresist layer is formed on the top surface of the first mask layer, the photoresist layer having an etching window exposing the second portion, the cap layer, the upper cladding layer, the upper waveguide layer, the active layer and a partial thickness of the lower waveguide layer located in the second portion are removed through the etching window to form the waveguide structure, and then the photoresist layer and the first mask layer are removed.

10. The method for preparing a high-power quantum cascade laser according to claim 1, characterized in that: The energy of the ion implantation is in the range of 50keV to 500keV, and the implantation dose of the ion implantation is in the range of 2E12cm -2 ~5E15cm -2 within the range.

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