Lateral composite photonic crystal semiconductor laser

Abstract

The invention provides a lateral composite photonic crystal semiconductor laser which can be applied to the technical field of artificial micro-nano structures and semiconductor lasers. The laser comprises a gain main array etched on an epitaxial structure, a loss lateral photonic crystal array and an additional microstructure, and the loss lateral photonic crystal array is located on at least one side of the gain main array; the additional microstructure is located on at least one side of at least one of the gain main array and the loss lateral photonic crystal array. A loss lateral photonic crystal array of a known gain main array is constructed through scanning matching of a transmission matrix method, and the loss lateral photonic crystal array and the loss lateral photonic crystal array are mutually coupled, so that the mode discrimination capability between a fundamental mode and a high-order mode of the laser is improved while the loss of a high-order side mode is improved, and single-mode laser output with the fundamental side mode as the main mode is obtained. The horizontal far-field divergence angle of the laser is reduced, and the lateral beam quality of the laser is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of artificial micro-nano structures and semiconductor lasers, and in particular to a lateral composite photonic crystal semiconductor laser. Background Art

[0002] Semiconductor lasers are small in size, high in conversion efficiency, and have a wide wavelength coverage range. Therefore, they can be used to pump solid-state lasers and fiber lasers, fiber-optic communications, and material processing. With the continuous development of the above applications, the requirements for laser performance are getting higher and higher. As one of the important ways to improve laser performance, single-mode output has become one of the important directions for the development of semiconductor laser technology. However, for ordinary semiconductor laser ridge waveguide structures, on the one hand, the output of the side mode is affected by the ridge waveguide. When the ridge waveguide width is small, it is conducive to achieving single-side mode output, but its output power is limited; and when the ridge waveguide width is large, although the output power is improved, it inevitably presents a multi-side mode output state; on the other hand, ordinary semiconductor lasers often lack microstructures other than the ridge waveguide for regulating the optical mode in the lateral direction, resulting in its lateral mode instability, and the optical properties are easily affected by carrier concentration and temperature changes. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In order to solve the technical problems existing in semiconductor lasers in the prior art, the embodiments of the present invention provide a lateral composite photonic crystal semiconductor laser, which constructs a lossy lateral photonic crystal array of a main array with known gain through scanning matching by the transmission matrix method, and couples the two with each other, thereby increasing the loss of high-order side modes and the mode discrimination ability between the fundamental mode and the high-order modes of the laser, thereby obtaining a single-mode laser output dominated by the fundamental side mode, reducing the horizontal far-field divergence angle of the laser, and improving the lateral beam quality of the laser.

[0005] (II) Technical solution

[0006] In view of the above problems, an embodiment of the present disclosure provides a lateral composite photonic crystal semiconductor laser.

[0007] According to a first aspect of the present disclosure, a lateral composite photonic crystal semiconductor laser is provided, comprising: a gain main array, a loss lateral photonic crystal array and an additional microstructure etched on an epitaxial structure, wherein the loss lateral photonic crystal array is located on at least one side of the gain main array; and the additional microstructure is located on at least one side of at least one of the gain main array and the loss lateral photonic crystal array.

[0008] In some exemplary embodiments, the epitaxial structure includes: an N-type substrate layer, used to support the semiconductor chip; an N-type buffer layer, used to reduce defects in epitaxial growth, located on the N-type substrate layer; an N-type confinement layer, used to limit the expansion of the light field, located on the side of the N-type buffer layer away from the N-type substrate layer; an active layer, used to recombine carriers and generate photons, located on the side of the N-type confinement layer away from the N-type substrate layer; a P-type confinement layer, used to limit the expansion of the light field, located on the side of the active layer away from the N-type substrate layer; and a P-type contact layer, used to form an ohmic contact with a metal electrode, located on the side of the P-type confinement layer away from the N-type substrate layer.

[0009] In some exemplary embodiments, the etching depth of the gain main array, the loss lateral photonic crystal array, and the additional microstructure on the epitaxial structure is at least from the P-type contact layer to the P-type confinement layer; and the etching depths of the gain main array, the loss lateral photonic crystal array, and the additional microstructure on the epitaxial structure are independent of each other.

[0010] In some exemplary embodiments, the waveguide units of the gain main array include a single waveguide or an arrayed waveguide; and at least part of the waveguide units of the gain main array are externally pumped and provide gain to promote fundamental side mode lasing.

[0011] In some exemplary embodiments, the waveguide units of the lossy lateral photonic crystal array have no external pumping; the lossy lateral photonic crystal array is capable of localized gain of the fundamental side mode of the gain main array; and the lossy lateral photonic crystal array is capable of expanding and losing at least part of the high-order side modes of the gain main array.

[0012] In some exemplary embodiments, the additional microstructure is manifested as a width chirp or an etching depth chirp of the waveguide unit of the gain main array or the loss lateral photonic crystal array, so as to enhance the coupling effect of the loss lateral photonic crystal array on the side mode of the gain main array, while increasing the loss capacity of the gain main array and the loss lateral photonic crystal array, and improving the dissipation of high-order side modes; and under the modulation effect of the additional microstructure, the gain main array and the loss lateral photonic crystal array are coupled with each other to form a lateral composite photonic crystal semiconductor laser, thereby realizing laser output dominated by the fundamental side mode.

[0013] In some exemplary embodiments, the shape of the additional microstructure includes at least one of a triangle, a rectangle and a circle; when the additional microstructure is located on both sides of the gain main array, the additional microstructures located on both sides of the gain main array can be symmetrical or asymmetrical with each other and can meet the requirements; when the additional microstructure is located on both sides of the loss side photonic crystal array, the additional microstructures located on both sides of the loss side photonic crystal array can be symmetrical or asymmetrical with each other and can meet the requirements; and the arrangement of the additional microstructures includes continuous connection arrangement in the longitudinal and lateral directions of the laser, periodic interval arrangement or non-periodic interval arrangement.

[0014] In some exemplary embodiments, the active layer includes a central single-layer or multi-layer quantum well and undoped waveguide layers that are symmetrically or asymmetrically distributed on both sides.

[0015] In some exemplary embodiments, the material of the single-layer or multi-layer quantum well includes an active dielectric material, wherein the active dielectric material includes one of a III-V semiconductor material or a II-VI semiconductor material; and the gain spectrum peak wavelength range of the active dielectric material covers the near ultraviolet to infrared band.

[0016] In some exemplary embodiments, materials of the N-type substrate layer, the N-type buffer layer, the N-type confinement layer, the P-type confinement layer, and the P-type contact layer include semiconductor materials.

[0017] (III) Beneficial effects

[0018] It can be seen from the above technical solutions that the lateral composite photonic crystal semiconductor laser provided by the embodiments of the present disclosure has at least one of the following beneficial effects:

[0019] (1) Through the transmission matrix method of scanning matching, a lossy lateral photonic crystal array with a known gain main array is constructed and the two are coupled to each other, so that the loss of the high-order side mode is increased and the mode discrimination ability between the fundamental mode and the high-order mode of the laser is increased, thereby obtaining a single-mode laser output dominated by the fundamental side mode, reducing the horizontal far-field divergence angle of the laser, and improving the lateral beam quality of the laser.

[0020] (2) The pumping method of the lateral composite photonic crystal semiconductor laser is current injection, which is convenient and feasible in experiments.

[0021] (3) It can be manufactured using common semiconductor processing techniques such as thin film growth, epitaxial growth, exposure, and corrosion, without the need for special processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0023] Figure 1 Schematically shows an oblique view of a first lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0024] Figure 2 Schematically shows a top view of a first lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0025] Figure 3 Schematically shows an oblique view of a second lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0026] Figure 4 Schematically shows a top view of a second lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0027] Figure 5 Schematically shows an oblique view of a third lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0028] Figure 6 Schematically shows a top view of a third lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0029] Figure 7 Schematically shows an oblique view of a fourth lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0030] Figure 8 Schematically shows a top view of a fourth lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0031] Fig. 9 Schematically shows a fundamental mode electric field distribution diagram of a lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0032] Fig.10 Schematically shows the first-order mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0033] Fig.11 A diagram schematically showing a second-order mode electric field distribution diagram of a lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure; and

[0034] Fig.12 The third-order mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0035] Reference numerals:

[0036] 1-N-type substrate layer; 2-N-type buffer layer; 3-N-type confinement layer; 4-active layer; 5-P-type confinement layer; 7-loss lateral photonic crystal array; 71-first loss lateral photonic crystal array; 72-second loss lateral photonic crystal array; 8-gain main array; 9-additional microstructure; 6-P-type contact layer. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0038] Figure 1 The figure schematically shows an oblique view of a first lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure. Figure 2 A top view of a first lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0039] like Figure 1 and Figure 2 As shown, the first lateral composite photonic crystal semiconductor laser according to the embodiment of the present disclosure includes a gain main array 8, a loss lateral photonic crystal array 7 and an additional microstructure 9 etched on an epitaxial structure, wherein the loss lateral photonic crystal array 7 is located on at least one side of the gain main array 8; and the additional microstructure 9 is located on at least one side of at least one of the gain main array 8 and the loss lateral photonic crystal array 7.

[0040] In the disclosed embodiment, the lossy lateral photonic crystal array 7 includes a first lossy lateral photonic crystal array 71 and a second lossy lateral photonic crystal array 72 , and the first lossy lateral photonic crystal array 71 and the second lossy lateral photonic crystal array 72 are respectively located on both sides of the gain main array 8 .

[0041] In the embodiment of the present disclosure, the epitaxial structure includes: an N-type substrate layer 1, used to support the semiconductor chip; an N-type buffer layer 2, used to reduce defects in epitaxial growth, located on the N-type substrate layer 1; an N-type confinement layer 3, used to limit the expansion of the light field, located on the side of the N-type buffer layer 2 away from the N-type substrate layer 1; an active layer 4, used to recombine carriers and generate photons, located on the side of the N-type confinement layer 3 away from the N-type substrate layer 1; a P-type confinement layer 5, used to limit the expansion of the light field, located on the side of the active layer 4 away from the N-type substrate layer 1; and a P-type contact layer 6, used to form an ohmic contact with a metal electrode, located on the side of the P-type confinement layer 5 away from the N-type substrate layer 1.

[0042] In the example of the present invention, a first loss lateral photonic crystal array 71 and a second loss lateral photonic crystal array 72 are constructed through photonic crystal energy bands and the two are coupled together with the gain main array 8 respectively, so that the loss of high-order side modes is increased and the mode discrimination ability between the fundamental mode and the high-order modes of the laser is increased, and the loss of each part to the high-order side modes is further enhanced by adding a microstructure 9 and the coupling ability of the loss lateral photonic crystal array 7 to the high-order side modes of the gain main array 8 is improved, thereby obtaining a laser output dominated by the fundamental side mode, reducing the horizontal divergence angle of the laser, and improving the lateral beam quality of the laser.

[0043] In some exemplary embodiments, the waveguide units of the gain main array 8 include one of a single waveguide or an arrayed waveguide; and at least part of the waveguide units of the gain main array 8 are externally pumped and provide gain to promote the lasing of the fundamental side mode; the left side of the gain main array 8 is a first loss side photonic crystal array 71, and the right side of the gain main array 8 is a second loss side photonic crystal array 72, the first loss side photonic crystal array 71 and the second loss side photonic crystal array 72 are both composed of one or more waveguide units without external pumping, and the loss side photonic crystal array 7 can locally gain the fundamental side mode of the gain main array 8; and the loss side photonic crystal array 7 can couple the high-order side modes of the gain main array 8 and dissipate the high-order side modes; additional microstructures 9 can enhance the dissipation capacity of high-order side modes and the coupling capacity of the loss side photonic crystal array 7 to the high-order side modes of the gain main array 8.

[0044] In some exemplary embodiments, the etching depth of the gain main array 8, the loss lateral photonic crystal array 7 and the additional microstructure 9 on the epitaxial structure is at least from the P-type contact layer to the P-type confinement layer 5; and the etching depths of the gain main array 8, the loss lateral photonic crystal array 7 and the additional microstructure 9 on the epitaxial structure are independent of each other. Optionally, the etching depth between each waveguide unit can be varied, and the etching depth between each waveguide unit can be independent of each other, and can use the same etching depth or different etching depths. The number and lateral position of the loss lateral photonic crystal array 7 can be varied, and the number of waveguide units of the loss lateral photonic crystal array 7 is an arbitrary value; the loss lateral photonic crystal array 7 can be located on the left side of the gain main array 8, or on the right side of the gain main array 8, or on both sides of the gain main array 8 at the same time; the loss lateral photonic crystal array 7 can be distributed periodically or non-periodically.

[0045] In some exemplary embodiments, the additional microstructure 9 is manifested as a width chirp or an etching depth chirp of the waveguide unit of the gain main array 8 or the loss lateral photonic crystal array 7, so as to enhance the coupling effect of the loss lateral photonic crystal array 7 on the side modes of the gain main array 8, while increasing the loss capacity of the gain main array 8 and the loss lateral photonic crystal array 7, and improving the dissipation of high-order side modes; and under the modulation effect of the additional microstructure 9, the gain main array 8 and the loss lateral photonic crystal array 7 are coupled with each other to form a lateral composite photonic crystal semiconductor laser, thereby realizing laser output dominated by the fundamental side mode.

[0046] In some exemplary embodiments, the position of the additional microstructure 9 can be variable, and can be located only on the gain main array 8, or only on the loss lateral photonic crystal array 7, or on both the gain main array 8 and the loss lateral photonic crystal array 7; for the additional microstructure 9 located on the loss lateral photonic crystal array 7, it can be located on the left side of the loss lateral photonic crystal array 7, or on the right side of the loss lateral photonic crystal array 7, or on both sides of the loss lateral photonic crystal array 7 at the same time. When located on both sides at the same time, the additional microstructures 9 on both sides can be symmetrical or asymmetrical with each other; for the additional microstructure 9 located on the gain main array 8, it can be located on the left side of the gain main array 8, on the right side of the gain main array 8, or on both sides of the gain main array 8 at the same time. When located on both sides at the same time, the additional microstructures 9 on both sides can be symmetrical or asymmetrical with each other. The arrangement of the additional microstructure 9 is variable. In the longitudinal and lateral directions of the laser, it can be arranged continuously, periodically, or non-periodically. The shape of the additional microstructure 9 is variable and can be various shapes such as triangle, rectangle, circle, etc.

[0047] In some exemplary embodiments, the active layer 4 includes a central single-layer or multi-layer quantum well and undoped waveguide layers symmetrically or asymmetrically distributed on both sides. The material of the single-layer or multi-layer quantum well includes an active dielectric material, wherein the active dielectric material includes one of a III-V semiconductor material or a II-VI semiconductor material; and the gain spectrum peak wavelength range of the active dielectric material covers the near ultraviolet to infrared band.

[0048] In some exemplary embodiments, the materials of the N-type substrate layer 1, the N-type buffer layer 2, the N-type confinement layer 3, the P-type confinement layer 5 and the P-type contact layer 6 include semiconductor materials. It is characterized in that the number of waveguide units of the gain main array 8 can be changed, and it can be a single waveguide or an arrayed waveguide.

[0049] In the disclosed embodiment, the waveguide width of the gain main array 8 is 16um; the waveguide width of the first loss lateral photonic crystal array 71 is 3.5um, and the interval between waveguides is 6um; the waveguide width of the second loss lateral photonic crystal array 72 is 6.5um, and the interval between waveguides is 3um; the structural unit of the additional microstructure 9 is an isosceles triangle with a base length of 4um and a height of 2um; the etching depth between the waveguides is 0.7um, the effective refractive index of the unetched area is 3.3472, and the effective refractive index of the etched area is 3.3459.

[0050] In the embodiment of the present invention, a structure for coupling high-order side modes is constructed by the lossy lateral photonic crystal arrays 7 on both sides of the gain main array 8, and the loss capacity of the photonic crystal is improved by the additional microstructure 9. At the same time, the chirp of the photonic crystal width generated by the additional microstructure 9 also enhances the coupling capacity to the high-order side modes in the gain main array 8. The lossy lateral photonic crystal array 7 adopts an interval coupling method, the first lossy lateral photonic crystal array 71 couples the second-order mode, and the second lossy lateral photonic crystal array 72 couples the first-order mode and the third-order mode, so as to achieve the effect of coupling the high-order side modes of the gain main array 8 and limiting the expansion of the fundamental side modes of the gain main array 8.

[0051] Figure 3 An oblique view of a second lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown. Figure 4 A top view of a second lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0052] like Figure 3 and Figure 4 As shown, according to the second lateral composite photonic crystal semiconductor laser of the embodiment of the present disclosure and Figure 1 and Figure 2 Compared with the first lateral composite photonic crystal semiconductor laser shown in the figure, the additional microstructure 9 in the first lateral composite photonic crystal semiconductor laser is only located on the sides of the first loss lateral photonic crystal array 71 and the second loss lateral photonic crystal array 72. According to the embodiment of the present disclosure, the additional microstructure 9 in the second lateral composite photonic crystal semiconductor laser is located both on the sides of the first loss lateral photonic crystal array 71 and the second loss lateral photonic crystal array 72 and on the sides of the gain main array 8.

[0053] In the disclosed embodiment, the waveguide width of the gain main array 8 is 16um; the waveguide width of the first loss lateral photonic crystal array 71 is 3.5um, and the interval between waveguides is 6um; the waveguide width of the second loss lateral photonic crystal array 72 is 6.5um, and the interval between waveguides is 3um; the structural unit of the additional microstructure 9 is an isosceles triangle with a base length of 4um and a height of 2um; the etching depth between the waveguides is 0.7um, the effective refractive index of the unetched area is 3.3472, and the effective refractive index of the etched area is 3.3459.

[0054] In the embodiment of the present invention, the loss capacity of the gain main array 8 itself to the high-order mode is improved by the additional microstructure 9 on the gain main array 8, the structure of coupling the high-order side mode is constructed by the loss lateral photonic crystal arrays 7 on both sides of the gain main array 8, and the loss capacity of the loss lateral photonic crystal array 7 is improved by the additional microstructure 9. At the same time, the chirp of the photonic crystal width generated by the additional microstructure 9 also enhances the coupling capacity to the high-order side mode in the gain main array 8. The loss lateral photonic crystal array 7 adopts an interval coupling method, the first loss lateral photonic crystal array 71 couples the second-order mode, and the second loss lateral photonic crystal array 72 couples the first-order mode and the third-order mode, so as to achieve the effect of coupling the high-order side mode of the gain main array 8 and limiting the expansion of the base side mode of the gain main array 8.

[0055] Figure 5 An oblique view of a third lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown. Figure 6 A top view of a third lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0056] like Figure 5 and Figure 6 As shown, according to the third lateral composite photonic crystal semiconductor laser of the embodiment of the present disclosure and Figure 1 and Figure 2 Compared with the first lateral composite photonic crystal semiconductor laser shown, the additional microstructure 9 in the first lateral composite photonic crystal semiconductor laser is located on the side of the first loss lateral photonic crystal array 71 and the second loss lateral photonic crystal array 72, and the additional microstructure 9 in the third lateral composite photonic crystal semiconductor laser according to the embodiment of the present disclosure is located on the side of the gain main array 8.

[0057] In the disclosed embodiment, the waveguide width of the gain main array 8 is 16um; the waveguide width of the first loss lateral photonic crystal array 71 is 3.5um, and the interval between waveguides is 6um; the waveguide width of the second loss lateral photonic crystal array 72 is 6.5um, and the interval between waveguides is 3um; the structural unit of the additional microstructure 9 is an isosceles triangle with a base length of 4um and a height of 2um; the etching depth between the waveguides is 0.7um, the effective refractive index of the unetched area is 3.3472, and the effective refractive index of the etched area is 3.3459.

[0058] In the disclosed embodiment, the additional microstructure 9 on the gain main array 8 improves the loss capacity of the gain main array 8 itself for high-order modes, and a structure for coupling high-order side modes is constructed through the loss lateral photonic crystal arrays 7 on both sides. The loss lateral photonic crystal arrays 7 adopt an interval coupling method, the first loss lateral photonic crystal array 71 couples the second-order mode, and the second loss lateral photonic crystal array 72 couples the first-order mode and the third-order mode, thereby achieving the effect of coupling the high-order side modes of the gain main array 8 and limiting the expansion of the fundamental side modes of the gain main array 8.

[0059] Figure 7 An oblique view of a fourth lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown. Figure 8 A top view of a fourth lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0060] like Figure 7 and Figure 8 As shown, according to the fourth lateral composite photonic crystal semiconductor laser of the embodiment of the present disclosure and Figure 5 and Figure 6 Compared with the third lateral composite photonic crystal semiconductor laser shown in the figure, the structural unit shape of the additional microstructure 9 of the third lateral composite photonic crystal semiconductor laser is an isosceles triangle, and the structural unit of the additional microstructure 9 of the fourth lateral composite photonic crystal semiconductor laser according to the embodiment of the present disclosure is a semicircle, and the structures of other parts are the same.

[0061] In the embodiment of the present disclosure, the structural unit of the additional microstructure 9 is semicircular, with a radius of 2 μm, and the other parameters are the same as Figure 5 and Figure 6 The third lateral compound photonic crystal semiconductor laser shown is the same.

[0062] Fig. 9 The fundamental mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0063] like Fig. 9As shown, according to the fundamental mode electric field of the lateral composite photonic crystal semiconductor laser according to the embodiment of the present disclosure, no obvious coupling effect occurs in the lossy lateral photonic crystal array 7, and the fundamental mode does not expand significantly.

[0064] Fig.10 The first-order mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0065] like Fig.10 As shown, from the first-order mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to the embodiment of the present disclosure, it can be seen that the first-order lateral mode is partially coupled to the second lossy lateral photonic crystal array 72, thereby increasing its loss.

[0066] Fig.11 The second-order mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0067] like Fig.11 As shown, according to the second-order mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to the embodiment of the present disclosure, it can be seen that the second-order lateral mode is partially coupled to the first lossy lateral photonic crystal array 71, thereby increasing its loss.

[0068] Fig.12 The third-order mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to an embodiment of the present disclosure is schematically shown.

[0069] like Fig.12 As shown, according to the third-order mode electric field distribution diagram of the lateral composite photonic crystal semiconductor laser according to the embodiment of the present disclosure, it can be seen that the third-order lateral mode is partially coupled to the second lossy lateral photonic crystal array 72, thereby increasing its loss.

[0070] Figure 1 to Figure 8 The distribution of each order mode in the embodiment of the present invention is consistent with Figure 9-12 Distribution map of .

[0071] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A lateral composite photonic crystal semiconductor laser, characterized in that: include: The gain main array, loss lateral photonic crystal array and additional microstructures etched on the epitaxial structure, Wherein, the loss lateral photonic crystal array is located on at least one side of the gain main array; The additional microstructure is located on at least one side of at least one of the gain main array and the loss lateral photonic crystal array.

2. The lateral composite photonic crystal semiconductor laser according to claim 1, characterized in that: The epitaxial structure comprises: N-type substrate layer, used to support the semiconductor chip; An N-type buffer layer, used to reduce defects in epitaxial growth, and located on the N-type substrate layer; An N-type limiting layer, used for limiting the expansion of the light field, located on a side of the N-type buffer layer away from the N-type substrate layer; An active layer, used for recombination of carriers and generation of photons, located on a side of the N-type confinement layer away from the N-type substrate layer; A P-type limiting layer, used for limiting the expansion of the light field, located on a side of the active layer away from the N-type substrate layer; and The P-type contact layer is used to form an ohmic contact with the metal electrode and is located on a side of the P-type restriction layer away from the N-type substrate layer.

3. The lateral composite photonic crystal semiconductor laser according to claim 2, characterized in that: The etching depth of the gain main array, the loss lateral photonic crystal array and the additional microstructure on the epitaxial structure is at least from the P-type contact layer to the P-type confinement layer; and The etching depths of the gain main array, the loss lateral photonic crystal array and the additional microstructure on the epitaxial structure are independent of each other.

4. The lateral composite photonic crystal semiconductor laser according to any one of claims 1 to 3, characterized in that: The waveguide unit of the gain main array includes one of a single waveguide or an arrayed waveguide; and At least part of the waveguide units of the gain main array are externally pumped and provide gain to promote fundamental side mode lasing.

5. The lateral composite photonic crystal semiconductor laser according to any one of claims 1 to 3, characterized in that: The waveguide unit of the lossy lateral photonic crystal array has no external pumping; The lossy lateral photonic crystal array is capable of locally gaining the fundamental side mode of the gain main array; and The lossy lateral photonic crystal array can expand and lose at least part of the high-order lateral modes of the gain main array.

6. The lateral composite photonic crystal semiconductor laser according to any one of claims 1 to 3, characterized in that: The additional microstructure is manifested as a width chirp or an etching depth chirp of a waveguide unit of a gain main array or a loss side photonic crystal array, so as to improve the coupling effect of the loss side photonic crystal array on the side mode of the gain main array, and at the same time increase the loss capacity of the gain main array and the loss side photonic crystal array, and improve the dissipation of high-order side modes; and Under the modulation of the additional microstructure, the gain main array and the loss lateral photonic crystal array are coupled to each other to form a lateral composite photonic crystal semiconductor laser, thereby realizing laser output dominated by the fundamental side mode.

7. The lateral composite photonic crystal semiconductor laser according to any one of claims 1 to 3, characterized in that: The shape of the additional microstructure includes at least one of a triangle, a rectangle and a circle; When the additional microstructures are located on both sides of the gain main array, the additional microstructures located on both sides of the gain main array can be symmetrical or asymmetrical with each other to meet the requirements; When the additional microstructures are located on both sides of the lossy side photonic crystal array, the additional microstructures located on both sides of the lossy side photonic crystal array can meet the requirements whether they are symmetrical or asymmetrical with each other; and The arrangement of the additional microstructures includes continuous arrangement in the longitudinal and lateral directions of the laser, periodic arrangement, or non-periodic arrangement.

8. The lateral composite photonic crystal semiconductor laser according to claim 2, characterized in that: The active layer includes a central single-layer or multi-layer quantum well and undoped waveguide layers that are symmetrically or asymmetrically distributed on both sides.

9. The lateral composite photonic crystal semiconductor laser according to claim 8, characterized in that: The material of the single-layer or multi-layer quantum well includes active dielectric material, Wherein, the active dielectric material comprises one of a III-V semiconductor material or a II-VI semiconductor material; and The gain spectrum peak wavelength range of the active dielectric material covers the near ultraviolet to infrared bands.

10. The lateral composite photonic crystal semiconductor laser according to claim 2, characterized in that: Materials of the N-type substrate layer, the N-type buffer layer, the N-type restriction layer, the P-type restriction layer and the P-type contact layer all include semiconductor materials.

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