High-order coupled mode laser

Abstract

The present disclosure provides a high-order coupled mode laser, which sequentially includes, from bottom to top: a lower electrode layer, an N-type substrate layer, an N-type confinement layer, an active layer, a P-type confinement layer, a P-type cover layer, an insulating layer, and an upper electrode layer; the waveguide structure is formed by etching the P-type cover layer and the P-type confinement layer, and includes at least one gain cavity and a plurality of loss cavities, and the loss cavities are symmetrically arranged on both sides of the gain cavity; a grating structure is further arranged on the gain cavity; an insulating layer is arranged on the upper surfaces of the gain cavity and the loss cavities, and a window area is arranged at the position corresponding to the gain cavity on the insulating layer; the gain of the gain cavity is regulated to couple the gain cavity with the loss cavities, and single-wavelength output is realized through the grating structure. The present disclosure realizes dual regulation of the transverse and longitudinal modes of the laser, realizes the regulation of the oscillation mode energy of the laser, realizes single-mode high-power laser output, high-bandwidth and high-rate direct modulation, and can be realized by using ordinary contact lithography, so as to greatly reduce the manufacturing cost of the laser.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor optoelectronic devices, and particularly to a high-order coupled mode laser. Background Art

[0002] With the continuous rise of mobile communication, big data, and cloud computing, various multimedia technologies in China have developed rapidly, and data services have experienced explosive growth, making Internet construction particularly important. Users' demands for higher bandwidth and higher speed have become increasingly urgent.

[0003] However, with the increase in this demand, problems have gradually emerged. Our current optical communication systems are facing the pressure of continuously increasing network capacity, which also means that we must improve the communication capacity and transmission rate as much as possible. One of the effective solutions to improve the communication capacity is to increase the modulation bandwidth of the light source. Although some technologies, such as advanced modulation format technologies and equalization technologies, can overcome the bandwidth limitations of the light source, they require high computational complexity and large power consumption. Therefore, using a broadband light source is still the most practical method. The directly modulated semiconductor laser has been a commonly used light source in optical communication systems due to a series of advantages such as simple structure, low insertion loss, large modulation bandwidth, small volume, high power conversion efficiency, easy integration with other devices, and long service life. The improvement of bandwidth is directly related to the photon lifetime and the number of photons that can be regulated per unit time. Most of the single-mode lasers required for direct modulation currently studied rely on single ridge strips (single cavities) to achieve. Although VCSEL lasers can break this limitation, they require extremely complex epitaxial technologies, with high manufacturing costs, and the cavity structure used is extremely short. Although the bandwidth is increased to a certain extent, it is not conducive to power improvement and relatively long-distance transmission.

[0004] In summary, there is an urgent need for a high-order coupled semiconductor laser with low cost and high production efficiency. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] The present disclosure provides a high-order coupled mode laser to solve the above-mentioned technical problems.

[0007] (2) Technical Solutions

[0008] According to one aspect of the present disclosure, there is provided a high-order coupled mode laser, which sequentially includes, from bottom to top: a lower electrode layer, an N-type substrate layer, an N-type confinement layer, an active layer, a P-type confinement layer, a P-type cover layer, an insulating layer, and an upper electrode layer;

[0009] A waveguide structure formed by an etched P-type cap layer and a P-type confinement layer; the waveguide structure includes: at least one gain cavity and a plurality of loss cavities, and the loss cavities are symmetrically arranged on both sides of the gain cavity;

[0010] A grating structure is further provided on the gain cavity;

[0011] An insulating layer is provided on the upper surfaces of the gain cavity and the loss cavities, and a window region is provided at a position corresponding to the gain cavity on the insulating layer;

[0012] Adjust the gain of the gain cavity to couple the gain cavity with the loss cavity, and achieve single-wavelength output through the grating structure.

[0013] In some embodiments of the present disclosure, the grating is also provided on the non-gain waveguide.

[0014] In some embodiments of the present disclosure, the grating structure is provided on the upper surface and / or side surface of the gain cavity.

[0015] In some embodiments of the present disclosure, the gain cavity is a plurality of gain waveguides provided in the waveguide layer; the loss cavity is a plurality of non-gain waveguides provided in the waveguide layer; the plurality of gain waveguides and the non-gain waveguides are in a ridge-like structure and are arranged parallel to each other.

[0016] In some embodiments of the present disclosure, two of the gain waveguides and two of the non-gain waveguides sequentially serve as a loss cavity, a gain cavity, a gain cavity, and a loss cavity.

[0017] In some embodiments of the present disclosure, the width of the high-order coupled mode laser is 220 micrometers to 400 micrometers; the length is 150 micrometers to 800 micrometers.

[0018] In some embodiments of the present disclosure, the width of the gain cavity is 1 micrometer to 10 micrometers; the length is 150 micrometers to 800 micrometers.

[0019] In some embodiments of the present disclosure, the width of the loss cavity is 2 micrometers to 4 micrometers; the length is 150 micrometers to 800 micrometers.

[0020] In some embodiments of the present disclosure, the distance between the gain cavity and the loss cavity is 3 micrometers to 6 micrometers; the distance between adjacent two gain cavities is 3 micrometers to 6 micrometers.

[0021] In some embodiments of the present disclosure, the material of the active layer is a gain medium material, and the gain medium material includes aluminum indium gallium arsenide or indium gallium arsenide phosphide.

[0022] (III) Beneficial effects

[0023] As can be seen from the above technical solutions, the high-order coupled mode laser of the present disclosure has at least one or a part of the following beneficial effects:

[0024] (1) The present disclosure is composed of multiple cavities, which is beneficial to power improvement.

[0025] (2) The laser provided by the present disclosure realizes the output of single transverse mode and single longitudinal mode through dual regulation in the transverse and longitudinal directions.

[0026] (3) While reducing the photon lifetime, the present disclosure ensures a high number of photons, which is beneficial to the improvement of the modulation bandwidth.

[0027] (4) On the premise of having multiple gain cavities, the laser provided by the present disclosure can utilize the photo photo resonance effect (PPR) to greatly improve the bandwidth.

[0028] (5) The characteristic size of the high-order grating adopted by the present disclosure can be greater than 1 micron, which can effectively avoid high-cost processing techniques such as electron beam lithography and is fabricated by ordinary contact lithography, reducing costs.

[0029] (6) The manufacturing process adopted by the present disclosure avoids multiple epitaxies, improves the robustness of the device, shortens the production time, and improves the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a three-dimensional structural schematic diagram of the high-order coupled mode laser of the first embodiment of the present disclosure.

[0031] Figure 2 is a front view structural schematic diagram of the high-order coupled mode laser of the first embodiment of the present disclosure.

[0032] Figure 3 is a top view structural schematic diagram of the high-order coupled mode laser of the first embodiment of the present disclosure.

[0033] Figure 4 is the high-order grating emission spectrum of the high-order coupled mode laser of the first embodiment of the present disclosure.

[0034] Figure 5 is a three-dimensional structural schematic diagram of the high-order coupled mode laser of the second embodiment of the present disclosure.

[0035] Figure 6 is a front view structural schematic diagram of the high-order coupled mode laser of the second embodiment of the present disclosure.

[0036] Figure 7 is a top view structural schematic diagram of the high-order coupled mode laser of the second embodiment of the present disclosure.

[0037] Figure 8This is the high-order grating emission spectrum of the high-order coupled mode laser in the second embodiment of the present disclosure.

[0038]

Explanation of the main element symbols in the embodiments of the present disclosure in the drawings

[0039] 10 - Lower electrode layer;

[0040] 20 - N-type substrate layer;

[0041] 30 - N-type confinement layer;

[0042] 40 - Active layer;

[0043] 50 - P-type confinement layer;

[0044] 60 - P-type capping layer;

[0045] 70 - Insulating layer;

[0046] 80 - Upper electrode layer;

[0047] 90 - Waveguide structure;

[0048] 91 - Gain cavity;

[0049] 92 - Loss cavity;

[0050] 100 - Grating structure. Detailed implementation manners

[0051] The present disclosure provides a high-order coupled mode laser, which sequentially includes, from bottom to top: a lower electrode layer, an N-type substrate layer, an N-type confinement layer, an active layer, a P-type confinement layer, a P-type capping layer, an insulating layer, and an upper electrode layer; the waveguide structure is formed by etching the P-type capping layer and the P-type confinement layer; the waveguide structure includes at least one gain cavity and a plurality of loss cavities, and the loss cavities are symmetrically arranged on both sides of the gain cavity; a grating structure is further arranged on the gain cavity; an insulating layer is arranged on the upper surfaces of the gain cavity and the loss cavities, and a window area is arranged at the position corresponding to the gain cavity on the insulating layer; the upper electrode layer is arranged on the window area of the insulating layer; the gain of the gain cavity is adjusted to couple the gain cavity with the loss cavity, and single-wavelength output is achieved through the grating structure. The present disclosure realizes dual regulation of the transverse and longitudinal modes of the laser, realizes the regulation of the oscillation mode energy of the laser, realizes single-mode high-power laser output, high-bandwidth and high-rate direct modulation, and can be realized by ordinary contact lithography, so as to greatly reduce the manufacturing cost of the laser.

[0052] To make the purpose, technical solution, and advantages of the present disclosure clearer and more understandable, the following further details the present disclosure with reference to specific embodiments and the accompanying drawings.

[0053] Certain embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments are shown. In fact, the various embodiments of the present disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will satisfy applicable legal requirements.

[0054] In a first exemplary embodiment of the present disclosure, a high-order coupled mode laser is provided. Figure 1 FIG. 1 is a perspective structural view of the high-order coupled mode laser according to the first embodiment of the present disclosure. Figure 2 FIG. 2 is a front structural view of the high-order coupled mode laser according to the first embodiment of the present disclosure. Figure 3 FIG. 3 is a top structural view of the high-order coupled mode laser according to the first embodiment of the present disclosure. As Figures 1 to 3 shown, the high-order coupled mode laser provided by the present disclosure sequentially includes, from bottom to top: a lower electrode layer 10, an N-type substrate layer 20, an N-type confinement layer 30, an active layer 40, a P-type confinement layer 50, a P-type cap layer 60, an insulating layer 70, and an upper electrode layer 80. The waveguide structure 90 is formed by etching the P-type cap layer 60 and the P-type confinement layer 50.

[0055] The waveguide structure 90 includes at least one gain cavity 91 and a plurality of loss cavities 92, and the loss cavities 92 are symmetrically arranged on both sides of the gain cavity 91. For example, the high-order coupled mode laser provided in this embodiment includes two gain cavities 91 and two loss cavities 92, and they are sequentially arranged as loss cavity 92, gain cavity 91, gain cavity 91, and loss cavity 92 on the waveguide layer 90.

[0056] Regarding the gain cavity 91, it is a plurality of gain waveguides provided in the waveguide structure 90. For example, it can be one, two, or three, and no further examples will be given here.

[0057] Regarding the loss cavity 92, it is a plurality of non-gain waveguides provided in the waveguide structure 90. For example, it can be one, two, or three, and no further examples will be given here.

[0058] Regarding the distribution of the ridge-shaped structures on the waveguide structure 90, the plurality of gain waveguides and the non-gain waveguides are in ridge-shaped structures and are arranged parallel to each other. As Figures 1 - 3 shown, the sizes of the gain cavity 91 and the loss cavity 92 are not the same, and the distances between two adjacent gain cavities 91 and the distances between the gain cavity 91 and the loss cavity 92 are also not the same.

[0059] The specific structures of the gain waveguide and the gain waveguide are further described as follows:

[0060] The width w1 of the loss cavity 92 is 2 to 4 micrometers, preferably 2.5 micrometers; the length l is 150 to 800 micrometers, preferably 500 micrometers.

[0061] The width w2 of the gain cavity 91 is from 1 μm to 10 μm, preferably 3 μm; the length l is from 150 μm to 800 μm, preferably 500 μm. The distance d2 between two adjacent gain cavities 91 is from 1 μm to 3 μm, preferably 2 μm.

[0062] The distance d1 between the gain cavity 91 and the loss cavity 92 is from 3 μm to 6 μm, preferably 4 μm.

[0063] The width w of the high-order coupled mode laser is from 220 μm to 400 μm, preferably 300 μm; the length l is from 150 μm to 800 μm, preferably 500 μm.

[0064] Regarding the grating structure 100, it is disposed at any position on the gain cavity 91. For example, it is the upper surface of the gain cavity 91 or the lateral grating structure 100 at the same height as the gain cavity 91. The etching depth of the gain waveguide, non-gain waveguide, and grating structure 100 is determined according to the structure of the grown waveguide structure 90, generally from 1.5 μm to 1.85 μm.

[0065] After etching the ridge-shaped structure and the grating structure 100, an insulating layer 70 needs to be grown above to achieve the effect of electrical isolation. Subsequently, an ICP etching or corrosion method is used to open a window area at the insulating layer 70 above the middle gain cavity 91, and a metal material is respectively covered on the window area of the insulating layer 70 and the lower surface of the N-type substrate layer 20 by magnetron sputtering or evaporation to form the upper electrode layer 80 and the lower electrode layer 10 for current injection. The ridge-shaped structures of the two side loss cavities 92 do not have electrical injection windows and become non-gain waveguides. The modes in the non-gain waveguides are coupled with those in the gain waveguides, and the high-order transverse modes can be coupled out. Longitudinally, the mode selection characteristics of the high-order gratings can achieve single-wavelength output. Finally, dual regulation of the transverse and longitudinal modes is realized to adjust the energy of the laser oscillation mode and achieve single-mode output of the multi-cavity laser.

[0066] In this embodiment, the thickness of the insulating layer 70 can be 300 nm.

[0067] In this embodiment, the material of the active layer 40 is a gain medium material, and the gain medium material includes aluminum indium gallium arsenide or indium gallium arsenide phosphide. The materials of the upper electrode layer 80 and the lower electrode layer 10 are conductive materials, such as titanium gold and gold germanium nickel gold.

[0068] Figure 4 This is the high-order grating emission spectrum of the high-order coupled mode laser in the first embodiment of the present disclosure. As Figure 4 shown, taking the forty-first order grating as an example, within the actual application range, there is only one reflection peak, and the peak wavelength is near 1557 nm.

[0069] In the second exemplary embodiment of the present disclosure, a high-order coupled mode laser is provided. Figure 5 FIG. is a schematic three-dimensional structure diagram of the high-order coupled mode laser according to the second embodiment of the present disclosure. Figure 6 FIG. is a schematic front view structure diagram of the high-order coupled mode laser according to the second embodiment of the present disclosure. Figure 7 FIG. is a schematic top view structure diagram of the high-order coupled mode laser according to the second embodiment of the present disclosure. As Figures 5 to 7 shown, compared with the high-order coupled mode laser of the first embodiment, the difference of the high-order coupled mode laser of this embodiment lies in that the grating structure 100 is also provided on the loss cavity 92.

[0070] For the purpose of brief description, any technical features that can be applied in the same way in the above first embodiment are incorporated herein and will not be repeated.

[0071] Figure 8 FIG. is the high-order grating emission spectrum of the high-order coupled mode laser according to the second embodiment of the present disclosure. As Figure 8 shown, taking the forty-first order grating as an example, within the actual application range, there is only one reflection peak, and the peak wavelength is near 1557 nanometers.

[0072] So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that, in the accompanying drawings or the text of the specification, the implementation manners that are not shown or described are all forms known to those of ordinary skill in the art and will not be described in detail. In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or manners mentioned in the embodiments, and those of ordinary skill in the art can make simple changes or substitutions thereto.

[0073] Based on the above description, those skilled in the art should have a clear understanding of the high-order coupled mode laser of the present disclosure.

[0074] In summary, the present disclosure provides a high-order coupled mode laser that can achieve dual regulation of the transverse and longitudinal modes of the laser, can achieve adjustment of the energy of the oscillation mode of the laser, and can achieve single-mode high-power laser output. The high-bandwidth and high-rate direct modulation of the present disclosure can be realized by using ordinary contact lithography, so as to greatly reduce the manufacturing cost of the laser.

[0075] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only references to the directions in the accompanying drawings and are not used to limit the protection scope of the present disclosure. Throughout the accompanying drawings, the same elements are denoted by the same or similar reference numerals. When it may cause confusion in the understanding of the present disclosure, the conventional structures or configurations will be omitted.

[0076] Moreover, the shapes and sizes of the components in the figures do not reflect the actual sizes and proportions, but merely illustrate the content of the embodiments of the present disclosure. Additionally, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claims.

[0077] Unless otherwise noted as having a contrary meaning, the numerical parameters in this specification and the appended claims are approximate values and can be changed according to the desired characteristics obtained through the content of the present disclosure. Specifically, all numbers used in the specification and claims to represent the contents of components, reaction conditions, etc. should be understood to be modified by the term "about" in all cases. Generally, the meaning expressed is that it includes a change of ±10% in some embodiments, a change of ±5% in some embodiments, a change of ±1% in some embodiments, and a change of ±0.5% in some embodiments for a specific quantity.

[0078] Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0079] Similarly, it should be understood that, in order to streamline the present disclosure and assist in understanding one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together in a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting the intention that the claimed present disclosure requires more features than those expressly recited in each claim. Rather, as reflected in the following claims, the disclosed aspects lie in less than all the features of the single preceding disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim itself serves as a separate embodiment of the present disclosure.

[0080] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present disclosure. It should be understood that the above description is only for the specific embodiments of the present disclosure and is not used to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A high-order coupled-mode laser, sequentially including from bottom to top: The lower electrode layer, N-type substrate layer, N-type confinement layer, active layer, P-type confinement layer, P-type cap layer, insulating layer, and upper electrode layer; A waveguide structure formed by etching the P-type cap layer and the P-type confinement layer; The waveguide structure includes: at least one gain cavity and a plurality of loss cavities, and the loss cavities are symmetrically arranged on both sides of the gain cavity; A grating structure is further arranged on the gain cavity; An insulating layer is arranged on the upper surfaces of the gain cavity and the loss cavity, and a window region is arranged at a position corresponding to the gain cavity on the insulating layer; The upper electrode layer is arranged on the window region; The gain cavity is a plurality of gain waveguides arranged in the waveguide structure; the loss cavity is a plurality of non-gain waveguides arranged in the waveguide structure; Adjust the gain of the gain cavity to couple the modes in the non-gain waveguide and the gain waveguide, and couple out the high-order transverse modes; longitudinally, the mode selection characteristic of the grating structure realizes single-wavelength output.

2. The high-order coupled mode laser according to claim 1, wherein, The grating is also arranged on the non-gain waveguide.

3. The high-order coupled mode laser according to claim 1 or 2, wherein, The grating structure is arranged on the upper surface and / or side surface of the gain cavity.

4. The high-order coupled mode laser according to claim 1, wherein, The plurality of gain waveguides and the non-gain waveguides are in a ridge-like structure and are arranged parallel to each other.

5. The high-order coupled mode laser according to claim 1, wherein, Two of the gain waveguides and two of the non-gain waveguides sequentially serve as a loss cavity, a gain cavity, a gain cavity, and a loss cavity.

6. The high-order coupled mode laser according to claim 1, wherein, The width of the high-order coupled mode laser is 220 micrometers to 400 micrometers; the length is 150 micrometers to 800 micrometers.

7. The high-order coupled mode laser according to claim 1, wherein, The width of the gain cavity is 1 micrometer to 10 micrometers; the length is 150 micrometers to 800 micrometers.

8. The high-order coupled mode laser according to claim 1, wherein, The width of the loss cavity is 2 micrometers to 4 micrometers; the length is 150 micrometers to 800 micrometers.

9. The high-order coupled mode laser according to claim 1, wherein The distance between the gain cavity and the loss cavity is 3 micrometers to 6 micrometers; the distance between adjacent gain cavities is 1 micrometer to 3 micrometers.

10. The high-order coupled mode laser according to claim 1, wherein, The material of the active layer is a gain medium material, and the gain medium material includes aluminum indium gallium arsenide or indium gallium arsenide phosphide.

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