Laterally composite photonic crystal semiconductor laser

Abstract

This disclosure provides a laterally composite photonic crystal semiconductor laser, applicable to the fields of artificial micro / nano structures and semiconductor lasers. The laser includes: a gain master array etched on an epitaxial structure, a loss lateral photonic crystal array, and additional microstructures. The loss lateral photonic crystal array is located on at least one side of the gain master array; the additional microstructures are located on at least one side of at least one of the gain master array and the loss lateral photonic crystal array. By using a transfer matrix method for scanning matching, a loss lateral photonic crystal array with a known gain master array is constructed, and the two are coupled together. This improves the loss of higher-order side modes while increasing the mode discrimination capability between the laser's fundamental mode and higher-order modes, thereby obtaining a single-mode laser output dominated by the fundamental and side modes, reducing the horizontal far-field divergence angle of the laser, and improving the lateral beam quality of the laser.

Description

Technical Field

[0001] This disclosure relates to the fields of artificial micro / nano structures and semiconductor lasers, and particularly to a lateral composite photonic crystal semiconductor laser. Background Technology

[0002] Semiconductor lasers are small in size, have high conversion efficiency, and cover a wide wavelength range, making them suitable for pumping solid-state lasers and fiber lasers, fiber optic communication, and materials processing. With the continuous development of these applications, the performance requirements for lasers are becoming increasingly stringent. Single-mode output, as a crucial way to improve laser performance, has become a key direction for the development of semiconductor laser technology. However, for ordinary semiconductor lasers with ridge waveguide structures, on the one hand, the side-mode output is affected by the ridge waveguide. When the ridge waveguide width is small, it is beneficial to achieve single-side-mode output, but its output power is limited; while when the ridge waveguide width is large, although the output power is improved, multi-side-mode output is inevitable. On the other hand, ordinary semiconductor lasers often lack microstructures other than the ridge waveguide for controlling optical modes in the lateral direction, leading to unstable lateral modes and optical characteristics that are easily affected by carrier concentration and temperature changes. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the technical problems existing in semiconductor lasers in the prior art, embodiments of this disclosure provide a side-recombining photonic crystal semiconductor laser. By scanning and matching using the transfer matrix method, a lossy side-recombining photonic crystal array with a known gain master array is constructed, and the two are coupled together. This improves the loss of higher-order side modes while increasing the mode discrimination capability between the laser's fundamental mode and higher-order modes, thereby obtaining a single-mode laser output dominated by the fundamental and side modes, reducing the horizontal far-field divergence angle of the laser, and improving the side beam quality of the laser.

[0005] (II) Technical Solution

[0006] In view of the above problems, embodiments of this disclosure provide a laterally composite photonic crystal semiconductor laser.

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

[0008] In some exemplary embodiments, the epitaxial structure includes: an N-type substrate layer for supporting a semiconductor chip; an N-type buffer layer for reducing defects in epitaxial growth, located on the N-type substrate layer; an N-type confinement layer for confining the spread of the light field, located on the side of the N-type buffer layer away from the N-type substrate layer; an active layer for recombination of charge carriers and generation of photons, located on the side of the N-type confinement layer away from the N-type substrate layer; a P-type confinement layer for confining the spread 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 for forming 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 master 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 depth of the gain master array, the loss lateral photonic crystal array, and the additional microstructure on the epitaxial structure is independent of each other.

[0010] In some exemplary embodiments, the waveguide elements of the gain master array include a single waveguide or an array of waveguides; and at least a portion of the waveguide elements of the gain master array are externally pumped and provided with gain to induce base-side mode lasing.

[0011] In some exemplary embodiments, the waveguide units of the loss-side photonic crystal array are not externally pumped; the loss-side photonic crystal array is capable of localizing the gain of the base-side modes of the main array; and the loss-side photonic crystal array is capable of extending and losing at least some of the higher-order side modes of the main array.

[0012] In some exemplary embodiments, the additional microstructure manifests as width chirp or etching depth chirp of the waveguide units of the gain master array or loss lateral photonic crystal array to improve the coupling effect of the loss lateral photonic crystal array to the side modes of the gain master array, while increasing the loss capability of the gain master array and the loss lateral photonic crystal array, and improving the dissipation of higher-order side modes; and under the modulation effect of the additional microstructure, the gain master array and the loss lateral photonic crystal array are coupled to each other to form a lateral composite photonic crystal semiconductor laser, realizing laser output dominated by the base-side mode.

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

[0014] In some exemplary embodiments, the active layer includes a central single-layer or multi-layer quantum well and undoped waveguide layers distributed symmetrically or asymmetrically 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 group III-V semiconductor material or a group II-VI semiconductor material; and the peak wavelength range of the gain spectrum of the active dielectric material covers the near-ultraviolet to infrared band.

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

[0017] (III) Beneficial Effects

[0018] As can be seen from the above technical solutions, the lateral recombination photonic crystal semiconductor laser provided by the embodiments of this disclosure has at least one of the following beneficial effects:

[0019] (1) By scanning and matching using the transfer matrix method, a lossy lateral photonic crystal array with a known gain master array is constructed and the two are coupled together, thereby increasing the loss of the higher-order side modes and increasing the mode discrimination capability between the fundamental mode and the higher-order modes of the laser, thus obtaining a single-mode laser output dominated by the fundamental side modes, 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 fabricated using common semiconductor processing techniques such as thin film growth, epitaxial growth, exposure, and etching, without the need for special processes. Attached Figure Description

[0022] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0023] Figure 1 A perspective view of a first lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown schematically.

[0024] Figure 2 A schematic top view of a first lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown;

[0025] Figure 3 A perspective view of a second lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown schematically.

[0026] Figure 4 A top view schematically illustrates a second lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0027] Figure 5 A perspective view of a third lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown schematically.

[0028] Figure 6 A top view schematically illustrates a third lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0029] Figure 7 A perspective view of a fourth lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown schematically.

[0030] Figure 8 A top view schematically illustrates a fourth lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0031] Figure 9 The diagram schematically illustrates the fundamental mode electric field distribution of a lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0032] Figure 10 The diagram schematically illustrates the first-order mode electric field distribution of a laterally recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure;

[0033] Figure 11 The diagram schematically illustrates the second-order mode electric field distribution of a lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure; and

[0034] Figure 12 The diagram schematically illustrates the third-order mode electric field distribution of a laterally recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure.

[0035] Figure label:

[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-side photonic crystal array; 71-First loss-side photonic crystal array; 72-Second loss-side photonic crystal array; 8-Gain main array; 9-Additional microstructure; 6-P-type contact layer. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0038] Figure 1 A perspective view of a first lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown schematically. Figure 2 A schematic top view of a first lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown.

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

[0040] In this embodiment of the disclosure, the loss-side photonic crystal array 7 includes a first loss-side photonic crystal array 71 and a second loss-side photonic crystal array 72, which are located on both sides of the gain main array 8.

[0041] In this embodiment of the disclosure, the epitaxial structure includes: an N-type substrate layer 1 for supporting a semiconductor chip; an N-type buffer layer 2 for reducing defects in epitaxial growth, located on the N-type substrate layer 1; an N-type confinement layer 3 for confining the spread 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 for recombination of charge carriers and generation of 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 for confining the spread 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 for forming 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 this invention, a first loss-side photonic crystal array 71 and a second loss-side photonic crystal array 72 are constructed using photonic crystal band structures and coupled to a gain master array 8, respectively. This increases the loss of higher-order side modes, thereby enhancing the mode discrimination capability between the laser's fundamental mode and higher-order modes. Furthermore, the addition of microstructure 9 further enhances the loss of each part on higher-order side modes and improves the coupling capability of the loss-side photonic crystal array 7 to the gain master array 8 on higher-order side modes. This results in a laser output dominated by the fundamental side modes, reduces the horizontal divergence angle of the laser, and improves the side beam quality of the laser.

[0043] In some exemplary embodiments, the waveguide units of the gain master array 8 include a single waveguide or an array of waveguides; and at least a portion of the waveguide units of the gain master array 8 are externally pumped and provide gain to induce lasing of the fundamental side modes; a first loss-side photonic crystal array 71 is located to the left of the gain master array 8, and a second loss-side photonic crystal array 72 is located to the right of the gain master array 8. Both the first loss-side photonic crystal array 71 and the second loss-side photonic crystal array 72 are composed of one or more waveguide units without external pumps. The loss-side photonic crystal array 7 is capable of localizing the gain of the fundamental side modes of the gain master array 8; and the loss-side photonic crystal array 7 is capable of coupling and dissipating higher-order side modes of the gain master array 8; the additional microstructure 9 can enhance the dissipation capability of higher-order side modes and the coupling capability of the loss-side photonic crystal array 7 to the higher-order side modes of the gain master array 8.

[0044] In some exemplary embodiments, the etching depth of the gain master array 8, the loss lateral photonic crystal array 7, and the additional microstructure 9 on the epitaxial structure extends at least from the P-type contact layer to the P-type confinement layer 5; and the etching depths of the gain master 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, either using the same etching depth or using 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 in the loss lateral photonic crystal array 7 is arbitrary; the loss lateral photonic crystal array 7 can be located to the left of the gain master array 8, to the right of the gain master array 8, or simultaneously on both sides of the gain master array 8; the loss lateral photonic crystal array 7 can be periodically distributed or non-periodically distributed.

[0045] In some exemplary embodiments, the additional microstructure 9 manifests as the width chirp or etching depth chirp of the waveguide unit of the gain master array 8 or the loss side-mounted photonic crystal array 7, to improve the coupling effect of the loss side-mounted photonic crystal array 7 to the side modes of the gain master array 8, while increasing the loss capability of the gain master array 8 and the loss side-mounted photonic crystal array 7, and improving the dissipation of higher-order side modes; and under the modulation effect of the additional microstructure 9, the gain master array 8 and the loss side-mounted photonic crystal array 7 are coupled to each other to form a side-mounted composite photonic crystal semiconductor laser, realizing laser output dominated by the base-side mode.

[0046] In some exemplary embodiments, the position of the additional microstructure 9 can be varied. It can be located only on the gain main array 8, only on the loss-side photonic crystal array 7, or simultaneously on both the gain main array 8 and the loss-side photonic crystal array 7. For the additional microstructure 9 located on the loss-side photonic crystal array 7, it can be located on the left side of the loss-side photonic crystal array 7, on the right side of the loss-side photonic crystal array 7, or simultaneously on both sides of the loss-side photonic crystal array 7. When it is located on both sides, the additional microstructures 9 on both sides can be symmetrical or asymmetrical. 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 simultaneously on both sides of the gain main array 8. When it is located on both sides, the additional microstructures 9 on both sides can be symmetrical or asymmetrical. The arrangement of the additional microstructures 9 can be varied. They can be arranged continuously, periodically, or non-periodically in the longitudinal and lateral directions of the laser. The shape of the additional microstructures 9 can also be varied, including triangles, rectangles, circles, and other shapes.

[0047] In some exemplary embodiments, the active layer 4 includes a central single-layer or multi-layer quantum well and undoped waveguide layers distributed symmetrically or asymmetrically 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 group III-V semiconductor materials or group II-VI semiconductor materials; and the peak wavelength range of the gain spectrum 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, N-type buffer layer 2, N-type confinement layer 3, P-type confinement layer 5, and P-type contact layer 6 include semiconductor materials. The characteristic feature is that the number of waveguide elements in its gain main array 8 can vary; it can be a single waveguide or an array of waveguides.

[0049] In this embodiment, the waveguide width of the gain main array 8 is 16 μm; the waveguide width of the first loss lateral photonic crystal array 71 is 3.5 μm, and the waveguide spacing is 6 μm; the waveguide width of the second loss lateral photonic crystal array 72 is 6.5 μm, and the waveguide spacing is 3 μm; the structural unit of the additional microstructure 9 is an isosceles triangle with a base length of 4 μm and a height of 2 μm; the etching depth between waveguides is 0.7 μm, 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 this embodiment of the invention, a structure coupling higher-order side modes is constructed by the loss-side photonic crystal arrays 7 on both sides of the gain main array 8. Furthermore, the loss capability of the photonic crystal is improved by the additional microstructure 9. Simultaneously, the chirp in the photonic crystal width generated by the additional microstructure 9 further enhances the coupling capability of the higher-order side modes in the gain main array 8. The loss-side photonic crystal arrays 7 employ an interleaved coupling method: the first loss-side photonic crystal array 71 couples the second-order mode, and the second loss-side photonic crystal array 72 couples the first-order and third-order modes, thereby achieving the function of coupling the higher-order side modes of the gain main array 8 while limiting the expansion of the fundamental side modes of the gain main array 8.

[0051] Figure 3 A perspective view of a second type of laterally recombine photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown schematically. Figure 4 A top view schematically illustrates a second lateral recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure.

[0052] like Figure 3 and Figure 4 As shown, a second type of laterally recombination photonic crystal semiconductor laser according to an embodiment of this disclosure and Figure 1 and Figure 2 Compared to the first type of laterally composite photonic crystal semiconductor laser shown, the additional microstructure 9 in the first type of laterally composite photonic crystal semiconductor laser is located only on the sides of the first loss laterally composite photonic crystal array 71 and the second loss laterally composite photonic crystal array 72. In the second type of laterally composite photonic crystal semiconductor laser according to the embodiments of this disclosure, the additional microstructure 9 is located on the sides of both the first loss laterally composite photonic crystal array 71 and the second loss laterally composite photonic crystal array 72, as well as on the sides of the gain master array 8.

[0053] In this embodiment, the waveguide width of the gain main array 8 is 16 μm; the waveguide width of the first loss lateral photonic crystal array 71 is 3.5 μm, and the waveguide spacing is 6 μm; the waveguide width of the second loss lateral photonic crystal array 72 is 6.5 μm, and the waveguide spacing is 3 μm; the structural unit of the additional microstructure 9 is an isosceles triangle with a base length of 4 μm and a height of 2 μm; the etching depth between waveguides is 0.7 μm, 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 this embodiment of the invention, the additional microstructure 9 on the gain master array 8 improves the loss capability of the gain master array 8 itself for higher-order modes. The loss-side photonic crystal arrays 7 on both sides of the gain master array 8 construct a structure for coupling higher-order side modes. Furthermore, the additional microstructure 9 enhances the loss capability of the loss-side photonic crystal arrays 7. Simultaneously, the chirp in the photonic crystal width generated by the additional microstructure 9 further enhances the coupling capability for higher-order side modes in the gain master array 8. The loss-side photonic crystal arrays 7 employ an interleaved coupling method: the first loss-side photonic crystal array 71 couples a second-order mode, and the second loss-side photonic crystal array 72 couples a first-order and a third-order mode, thereby achieving the function of coupling higher-order side modes of the gain master array 8 while limiting the expansion of the fundamental side modes of the gain master array 8.

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

[0056] like Figure 5 and Figure 6 As shown, a third type of laterally recombination photonic crystal semiconductor laser according to an embodiment of this disclosure and Figure 1 and Figure 2 Compared to the first type of laterally composite photonic crystal semiconductor laser shown, the additional microstructure 9 in the first type of laterally composite photonic crystal semiconductor laser is located on the side of the first loss laterally composite photonic crystal array 71 and the second loss laterally composite photonic crystal array 72. In the third type of laterally composite photonic crystal semiconductor laser according to the embodiments of this disclosure, the additional microstructure 9 is located on the side of the gain master array 8.

[0057] In this embodiment, the waveguide width of the gain main array 8 is 16 μm; the waveguide width of the first loss lateral photonic crystal array 71 is 3.5 μm, and the waveguide spacing is 6 μm; the waveguide width of the second loss lateral photonic crystal array 72 is 6.5 μm, and the waveguide spacing is 3 μm; the structural unit of the additional microstructure 9 is an isosceles triangle with a base length of 4 μm and a height of 2 μm; the etching depth between waveguides is 0.7 μm, 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 this embodiment, the additional microstructure 9 on the gain master array 8 improves the loss capability of the gain master array 8 for higher-order modes. The loss-side photonic crystal arrays 7 on both sides construct a structure for coupling higher-order side modes. The loss-side photonic crystal arrays 7 adopt an intermittent coupling method. The first loss-side photonic crystal array 71 couples the second-order mode, and the second loss-side photonic crystal array 72 couples the first-order mode and the third-order mode, thereby realizing the function of coupling the higher-order side modes of the gain master array 8 and limiting the expansion of the base-side modes of the gain master array 8.

[0059] Figure 7 A perspective view of a fourth laterally recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure is shown schematically. Figure 8 A top view schematically illustrates a fourth laterally recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure.

[0060] like Figure 7 and Figure 8 As shown, a fourth type of laterally recombination photonic crystal semiconductor laser according to an embodiment of this disclosure and Figure 5 and Figure 6 Compared to the third type of laterally recombine photonic crystal semiconductor laser shown, the structural unit shape of the additional microstructure 9 of the third type of laterally recombine photonic crystal semiconductor laser is an isosceles triangle, while the structural unit shape of the additional microstructure 9 of the fourth type of laterally recombine photonic crystal semiconductor laser according to the present disclosure is a semi-circle, and the other parts are the same.

[0061] In this embodiment, the structural unit of the additional microstructure 9 is a semi-circle with a radius of 2 μm, and all other parameters are the same as those in the present invention. Figure 5 and Figure 6 The third type of lateral composite photonic crystal semiconductor laser shown is the same.

[0062] Figure 9 The diagram schematically illustrates the fundamental mode electric field distribution of a laterally recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure.

[0063] like Figure 9As shown, according to the fundamental mode electric field of the lateral composite photonic crystal semiconductor laser according to the embodiment of this disclosure, no obvious coupling effect is observed in the lossy lateral photonic crystal array 7, and the fundamental side mode does not show obvious expansion.

[0064] Figure 10 The diagram schematically illustrates the first-order mode electric field distribution of a laterally recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure.

[0065] like Figure 10 As shown in the diagram of the first-order mode electric field distribution of the lateral composite photonic crystal semiconductor laser according to the embodiment of this disclosure, the first-order side mode is coupled to the second lossy lateral photonic crystal array 72, which increases its loss.

[0066] Figure 11 The diagram schematically illustrates the second-order mode electric field distribution of a laterally recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure.

[0067] like Figure 11 As shown in the diagram of the second-order mode electric field distribution of the lateral composite photonic crystal semiconductor laser according to the embodiment of this disclosure, the second-order side mode is coupled to the first loss lateral photonic crystal array 71, which increases its loss.

[0068] Figure 12 The diagram schematically illustrates the third-order mode electric field distribution of a laterally recombination photonic crystal semiconductor laser according to an embodiment of the present disclosure.

[0069] like Figure 12 As shown in the diagram of the third-order mode electric field distribution of the lateral composite photonic crystal semiconductor laser according to the embodiment of this disclosure, the third-order side mode is coupled to the second loss lateral photonic crystal array 72, which increases its loss.

[0070] Figures 1-8 The distribution of each order mode in the embodiments is consistent with Figures 9-12 Distribution map.

[0071] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A lateral recombination photonic crystal semiconductor laser, characterized in that, include: The gain master array, loss lateral photonic crystal array, and additional microstructures are etched onto the epitaxial structure. The loss-biased 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 master array and the loss side-mounted photonic crystal array; The epitaxial structure includes: N-type substrate layer, used to support semiconductor chips; An N-type buffer layer, used to reduce defects in epitaxial growth, is located on the N-type substrate layer; An N-type confinement layer, used to confine the spread of the light field, is located on the side of the N-type buffer layer away from the N-type substrate layer; An active layer, used for recombination of charge carriers and generation of photons, is located on the side of the N-type confinement layer away from the N-type substrate layer; A P-type confinement layer, used to confine the spread of the optical field, is located on the side of the active layer away from the N-type substrate layer; and The P-type contact layer, used to form an ohmic contact with the metal electrode, is located on the side of the P-type confinement layer away from the N-type substrate layer; The etching depth of the gain master array, the loss lateral photonic crystal array, and the additional microstructure on the epitaxial structure extends at least from the P-type contact layer to the P-type confinement layer; and The etching depths of the gain master array, the loss lateral photonic crystal array, and the additional microstructure on the epitaxial structure are independent of each other; The additional microstructure manifests as width chirp or etching depth chirp of the waveguide units of the gain master array or loss lateral photonic crystal array, to improve the coupling effect of the loss lateral photonic crystal array to the side modes of the gain master array, while increasing the loss capability of both the gain master array and the loss lateral photonic crystal array, and improving the dissipation of higher-order side modes; and Under the modulation effect of the additional microstructure, the gain master array and the loss lateral photonic crystal array are coupled to form a lateral composite photonic crystal semiconductor laser, realizing laser output dominated by the base-side mode.

2. The lateral recombination photonic crystal semiconductor laser according to claim 1, characterized in that, The waveguide unit of the gain master array includes either a single waveguide or an arrayed waveguide; and At least some of the waveguide elements of the gain master array are externally pumped and provided with gain to induce base-side mode lasing.

3. The lateral recombination photonic crystal semiconductor laser according to claim 1, characterized in that, The waveguide units of the lossy lateral photonic crystal array are not externally pumped. The lossy lateral photonic crystal array can locally gain the base-side modes of the gain master array; and The lossy lateral photonic crystal array can extend and lose at least a portion of the higher-order side modes of the gain master array.

4. The lateral recombination photonic crystal semiconductor laser according to claim 1, characterized in that, The shape of the additional microstructure includes at least one of triangle, rectangle and circle; When the additional microstructures are located on both sides of the main gain array, the requirements can be met whether the additional microstructures on both sides of the main gain array are symmetrical or asymmetrical with each other. When the additional microstructures are located on both sides of the loss-side photonic crystal array, the requirement can be met whether the additional microstructures on both sides of the loss-side photonic crystal array are symmetrical or asymmetrical with each other; and The arrangement of the additional microstructures includes continuous longitudinal and lateral arrangement, periodic interval arrangement, or non-periodic interval arrangement of the laser.

5. The lateral recombination photonic crystal semiconductor laser according to claim 1, characterized in that, The active layer includes a central single-layer or multi-layer quantum well and undoped waveguide layers distributed symmetrically or asymmetrically on both sides.

6. The lateral recombination photonic crystal semiconductor laser according to claim 5, characterized in that, The materials of the single-layer or multi-layer quantum wells include active dielectric materials. The active dielectric material includes one of group III-V semiconductor materials or group II-VI semiconductor materials; and The peak wavelength range of the gain spectrum of the active dielectric material covers the near-ultraviolet to infrared band.

7. The lateral recombination photonic crystal semiconductor laser according to claim 1, characterized in that, The 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 all include semiconductor materials.

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