Active feedback laser and method of fabrication

Abstract

The active feedback laser and the preparation method provided by the present disclosure relate to the technical field of semiconductor lasers. The active feedback laser comprises: a first ridge waveguide for generating a first light beam through an injected first current; at least one second ridge waveguide electrically isolated from the first ridge waveguide for generating at least one second light beam, one second ridge waveguide generating one second light beam through an injected second current; and at least one third ridge waveguide passively connected to the first ridge waveguide and the at least one second ridge waveguide for coupling the received at least one second light beam into the first ridge waveguide; wherein in the first ridge waveguide, the received at least one second light beam and the first light beam form a photon-photon resonance effect.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of semiconductor lasers, and more particularly, to an active feedback laser and a preparation method. BACKGROUND

[0002] Distributed feedback Bragg lasers (DFB) have attracted extensive attention from academia and industry due to their high electro-optical conversion efficiency, small size, flexible structure, and excellent reliability. Their advantages include single-mode operation, monolithic integration, and low cost, which make them have significant advantages in various applications. The working principle of DFB lasers is based on the built-in distributed Bragg reflection grating, which is directly embedded or close to the active region, and the stable single-mode output is achieved by selectively feeding back photons of a specific wavelength, and the mode stability can be further optimized by introducing a λ / 4 phase shift. However, the current DFB laser has a small modulation bandwidth, which is not conducive to the application requirements of high-speed data transmission. SUMMARY

[0003] Therefore, the present disclosure provides an active feedback laser and a preparation method.

[0004] In one aspect, the present disclosure provides an active feedback laser, comprising: a first ridge waveguide for generating a first light beam by injecting a first current; at least one second ridge waveguide electrically isolated from the first ridge waveguide for generating at least one second light beam, one second ridge waveguide generating one second light beam by injecting a second current; at least one third ridge waveguide passively connected to the first ridge waveguide and the at least one second ridge waveguide for coupling the received at least one second light beam into the first ridge waveguide; wherein in the first ridge waveguide, the received at least one second light beam forms a photon-photon resonance effect with the first light beam.

[0005] According to an embodiment of the present disclosure, generating the at least one second light beam comprises: controlling the timing of the corresponding generated at least one second light beam by adjusting the size of the corresponding second current injected into the at least one second ridge waveguide.

[0006] According to an embodiment of the present disclosure, the at least one third ridge waveguide is further configured to adjust a first phase of the received at least one second light beam, so as to match the first phase with a second phase of the first light beam.

[0007] According to an embodiment of the present disclosure, adjusting the first phase of the received at least one second light beam comprises: injecting a third current into the at least one third ridge waveguide, and controlling the first phase of the at least one second light beam by controlling the size of the third current.

[0008] According to an embodiment of the present disclosure, the active feedback laser further comprises an N-type electrode, which is coplanar with the first ridge waveguide, the at least one second ridge waveguide, and the at least one third ridge waveguide.

[0009] The second aspect of the present disclosure provides an active feedback laser, comprising: a first ridge waveguide configured to generate a first light beam by injecting a first current; and at least one second ridge waveguide passively connected to the first ridge waveguide, configured to generate at least one second light beam and couple the at least one second light beam into the first ridge waveguide, so that the at least one second light beam and the first light beam form a photon-photon resonance effect; wherein one second ridge waveguide generates one second light beam by injecting a second current.

[0010] According to an embodiment of the present disclosure, the timing of the at least one second light beam generated by adjusting the size of the second current injected into the at least one second ridge waveguide corresponding to the at least one second light beam.

[0011] According to an embodiment of the present disclosure, the active feedback laser further comprises an N-type electrode, which is coplanar with the first ridge waveguide and the at least one second ridge waveguide.

[0012] According to an embodiment of the present disclosure, the active feedback laser further comprises a grating structure arranged on both sides of the first ridge waveguide.

[0013] The third aspect of the present disclosure provides a preparation method of an active feedback laser, comprising: epitaxially growing a growth structure on a substrate; etching a first ridge waveguide, at least one second ridge waveguide, and at least one third ridge waveguide on the growth structure; wherein the first ridge waveguide is configured to generate a first light beam by injecting a first current; the at least one second ridge waveguide is electrically isolated from the first ridge waveguide and is configured to generate at least one second light beam, and one second ridge waveguide generates one second light beam by injecting a second current; the at least one third ridge waveguide is passively connected to the first ridge waveguide and the at least one second ridge waveguide and is configured to couple the received at least one second light beam into the first ridge waveguide; and in the first ridge waveguide, the received at least one second light beam and the first light beam form a photon-photon resonance effect.

[0014] Alternatively, etching a first ridge waveguide and at least one second ridge waveguide on a growth structure; wherein the first ridge waveguide is configured to generate a first light beam by injecting a first current; and the at least one second ridge waveguide is passively connected to the first ridge waveguide and is configured to generate at least one second light beam and couple the at least one second light beam into the first ridge waveguide, so that the at least one second light beam and the first light beam form a photon-photon resonance effect; and one second ridge waveguide generates one second light beam by injecting a second current.

[0015] The active feedback laser provided by the embodiment of the present disclosure has at least the following beneficial effects:

[0016] The at least one second light beam is generated by injecting current into the at least one second ridge waveguide, which realizes independent control and flexible adjustment of the second ridge waveguide light source, avoids complex transmission paths, reduces signal loss and noise introduction caused by transmission, and is conducive to realizing higher modulation bandwidth.

[0017] In the case of electrical isolation between the first ridge waveguide and the second ridge waveguide, at least one third ridge waveguide is provided to couple the generated second light beam into the first ridge waveguide through passive connection, which avoids complex active modulation process and reduces loss and noise in the signal transmission path. In addition, by precisely controlling the current injection of the second ridge waveguide and the third ridge waveguide, the second light beam can be coupled into the first ridge waveguide at a specific time point and phase, thereby effectively improving the modulation bandwidth and high-speed performance.

[0018] The first ridge waveguide and the second ridge waveguide are directly and passively connected, directly generating and coupling the second light beam into the first ridge waveguide, which simplifies the complexity of the system, shortens the transmission path, reduces feedback delay, and helps to improve the response speed and high-speed characteristics of the system. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure, taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 An active feedback laser schematic diagram according to an embodiment of the present disclosure is schematically shown;

[0021] Figure 2 An A-A side view according to an embodiment of the present disclosure is schematically shown;

[0022] Figure 3 An active feedback laser schematic diagram according to another embodiment of the present disclosure is schematically shown;

[0023] Figure 4 An A-A side view according to another embodiment of the present disclosure is schematically shown;

[0024] Figure 5 A preparation method according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood, however, that the description is merely exemplary and is not intended to limit the scope of the present disclosure. In the following detailed description of the embodiments, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it would be apparent to those skilled in the art that the embodiments can be practiced without these specific details. In other instances, well-known systems and methods have not been described in detail in order to avoid unnecessarily obscuring the concepts of the present disclosure.

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the term "includes" and tautological expressions thereof, such as "including," "includes," "include," "contains," "containing," and so on, mean the presence of stated features, steps, operations, elements, and / or components but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0027] All terms used herein, including technical and scientific terms, have the meanings commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having meanings that are consistent with the context of the specification, and should not be interpreted in an idealized or overly formal manner.

[0028] In the case of using expressions similar to "at least one of A, B, and C, etc.", it should generally be interpreted to include any of them alone, any combination of two or more of them, as well as the case in which all of them are included, unless otherwise specified. For example, "a system having at least one of A, B, and C" should be interpreted to include a system having A alone, a system having B alone, a system having C alone, a system having A and B together, a system having A and C together, a system having B and C together, and a system having A, B, and C together, etc.

[0029] DFB lasers are grating mirrors that contain gain within the grating. According to the position of the grating in the device structure, the O-wave direct tuning DFB laser is mainly divided into two types: tunnel buried structure (Buried Waveguide DFB, abbreviated as BW-DFB) and ridge waveguide grating structure (Ridge Waveguide Distributed Feedback Laser, abbreviated as RGW-DFB). Among them, the BW-DFB structure needs to be etched after the grating and then second epitaxial growth, which will cause many internal defects of the material. In addition, this structure usually uses Zn to diffuse from the current blocking layer to the active region, which is easy to make the optical loss and parasitic capacitance of the p-n-p BH structure large. Compared with the tunnel buried structure, the RGW-DFB does not need second epitaxial growth, reduces the complex manufacturing steps, and reduces production costs and process difficulty. At the same time, because it does not need second epitaxial growth, it has fewer internal defects, lower parasitic capacitance and high stability, and is suitable for high-speed data transmission.

[0030] The present disclosure provides an active feedback laser, comprising:

[0031] A first ridge waveguide for generating a first light beam by injecting a first current.

[0032] At least one second ridge waveguide electrically isolated from the first ridge waveguide for generating at least one second light beam, one second ridge waveguide generating one second light beam by injecting a second current.

[0033] At least one third ridge waveguide passively connected to the first ridge waveguide and the at least one second ridge waveguide through a passive waveguide for coupling the received at least one second light beam into the first ridge waveguide.

[0034] Wherein, in the first ridge waveguide, the received at least one second light beam forms a photon-photon resonance (PPR) effect with the first light beam.

[0035] In an embodiment of the present disclosure, the first ridge waveguide serves as a main cavity, the at least one second ridge waveguide serves as a feedback cavity, and the at least one third ridge waveguide serves as a coupling cavity, all of which are arranged on the quantum well and quantum dot epitaxial structure, and the feedback and coupling can be combined to realize the coupling of the at least one second light beam into the main cavity to form the PPR effect.

[0036] By introducing the at least one second light beam and making it form the PPR effect with the first light beam in the first ridge waveguide, an additional response peak can be added outside the relaxation oscillation peak of the laser. This additional response peak helps to break through the relaxation bandwidth limitation of the traditional quantum dot laser, thereby improving the overall modulation bandwidth, which can be used in the O-band.

[0037] Each second ridge waveguide generates a light beam by an independently injected second current. This independent control can accurately adjust the output power, phase and other parameters of each feedback light source, avoiding unnecessary optical feedback and interference, thereby reducing optical loss. The second ridge waveguide is electrically isolated from the first ridge waveguide, which means that the electrical interaction between them is minimized, reducing additional noise and loss due to electrical crosstalk.

[0038] The third ridge waveguide is passively connected between the first ridge waveguide and the second ridge waveguide. Passive connection means that no additional active element is needed to guide the light beam, reducing the loss introduced by the active element.

[0039] Therefore, the second light beam generated in the present embodiment can be efficiently coupled into the first ridge waveguide, reducing optical loss, so that the second light beam forms a photon-photon resonance effect with the first light beam, having high modulation bandwidth and high high-speed characteristics.

[0040] Figure 1 An active feedback laser diagram according to an embodiment of the present disclosure is schematically shown.

[0041] Figure 2 An A-A side view is schematically shown according to an embodiment of the present disclosure.

[0042] In some possible embodiments, the number of the at least one second ridge waveguide can be 2, and the number of the at least one third ridge waveguide can be 2, but not limited thereto.

[0043] As Figure 1 shown, the active feedback laser includes: a first ridge waveguide 1 generates a first light beam by injecting a first current. Two second ridge waveguides 21 and 22 generate two second light beams by injecting a second current. The first ridge waveguide 1 is isolated from the second ridge waveguides 21 and 22 by electrical isolation 41 and 42. The third ridge waveguides 31 and 32 are passively connected to the first ridge waveguide 1 and the second ridge waveguides 21 and 22 through passive waveguides.

[0044] In the embodiment of the present disclosure, by providing multiple second ridge waveguides, additional optical feedback paths can be provided at different locations, which can break through the modulation bandwidth limitation caused by a single feedback path, further improve the overall modulation bandwidth, and have higher high-speed characteristics.

[0045] In the embodiment of the present disclosure, the active feedback laser further includes an N-type electrode 5.

[0046] On the basis of the above-mentioned embodiment, generating the at least one second light beam includes: controlling the timing of the at least one second light beam generated by adjusting the size of the second current injected into the at least one second ridge waveguide.

[0047] In the embodiment of the present disclosure, the photon-photon resonance effect depends on the interaction between photons of different frequencies. By precisely controlling the timing of the second light beams, the time at which these light beams reach the first ridge waveguide can be adjusted, thereby more effectively realizing the resonance between photons. And each second ridge waveguide has an independent current injection path, allowing the intensity of each second light beam to be adjusted individually. By changing the size of the second current, the output power of each second light beam can be controlled. By precisely controlling the size of the injected current, it is ensured that the second light beams enter the first ridge waveguide with the required timing. After the second light beams are coupled into the first ridge waveguide, they interact with the first light beam to form PPR. By precisely controlling the timing of the second light beams, the resonance effect can be optimized, thereby improving the oscillation frequency and stability of the first ridge waveguide, and further improving the high-speed characteristics of the laser.

[0048] Based on the above embodiment, the at least one third ridge waveguide is further configured to regulate the first phase of the at least one received second light beam by controlling the magnitude of an injected third current so that the first phase matches the second phase of the first light beam. This allows the at least one second light beam to be efficiently coupled into the first ridge waveguide. This optimizes the coupling effect of the second light beam from the second ridge waveguide to the first ridge waveguide and reduces optical losses.

[0049] On the basis of the above embodiment, the active feedback laser further includes: an N-type electrode 5 coplanar with the first ridge waveguide, at least one second ridge waveguide and at least one third ridge waveguide.

[0050] In the embodiments of the present disclosure, a coplanar electrode structure is utilized to reduce the current transmission path, lower the influence of parasitic resistance and parasitic capacitance, and increase bandwidth.

[0051] Based on the above embodiment, the active feedback laser further includes: a grating structure 6, which is arranged on both sides of the first ridge waveguide and both sides of at least one third ridge waveguide, and is used for selective feedback to achieve single-mode emission of the laser.

[0052] Figure 3 A schematic diagram of an active feedback laser according to another embodiment of the present disclosure is shown schematically.

[0053] Figure 4 FIG2 schematically shows an AA side view according to another embodiment of the present disclosure.

[0054] like Figure 3 and Figure 4 As shown, the present disclosure provides an active feedback laser, comprising:

[0055] The first ridge waveguide 1 is used to generate a first light beam by injecting a first current.

[0056] At least one second ridge waveguide is passively connected to the first ridge waveguide via the passive waveguide 7. It is used to generate at least one second light beam and couple the at least one second light beam into the first ridge waveguide so that the at least one second light beam forms a photon-photon resonance effect with the first light beam.

[0057] A second ridge waveguide generates a second light beam by injecting a second current.

[0058] In the embodiments of the present disclosure, the first ridge waveguide serves as the main cavity, and at least one second ridge waveguide serves as the feedback cavity. The main cavity and the feedback cavity are directly and passively connected, and both are arranged on the quantum well and quantum dot epitaxial structure, so that at least one second light beam can be coupled into the main cavity to form a PPR effect.

[0059] The second ridge waveguide is directly connected to the first ridge waveguide in a passive manner, and the generated second light beam is directly coupled into the first ridge waveguide, thereby avoiding optical loss caused by active modulation, simplifying the structure and shortening the transmission path of the light beam. Meanwhile, the second light beam is generated by independently regulating the injected second current, thereby improving the flexibility of adjustment.

[0060] For example, the number of the at least one second ridge waveguide can be selected as needed, such as Figure 3 As shown, the second ridge waveguide can be two, i.e., 21 and 22.

[0061] The active feedback laser includes: the first ridge waveguide 1 generates a first light beam by injecting a first current. The second ridge waveguide 21 and 22 generate two second light beams by injecting a second current. The first ridge waveguide 1 is connected to the second ridge waveguide 21 and 22 in a passive manner through a passive waveguide 7 and is arranged on an epitaxial wafer.

[0062] The first ridge waveguide 1 and the second ridge waveguide 21 and 22 are each provided with a corresponding GSG (Ground Signal Groun, ground-signal-ground) pin and are connected through an electrode lead. In the embodiment of the present disclosure, by arranging multiple second ridge waveguides, additional optical feedback paths can be provided at different positions, the modulation bandwidth limitation caused by a single feedback path can be broken through, the overall modulation bandwidth can be further improved, and higher high-speed characteristics can be achieved.

[0063] According to the embodiment of the present disclosure, the timing of the at least one second light beam generated by regulating the size of the second current injected into the at least one second ridge waveguide is controlled.

[0064] In the embodiment of the present disclosure, the size of the second current is independently controlled, and then the timing of the second light beam coupled into the first ridge waveguide is controlled, so as to achieve the maximum oscillation frequency of the main cavity, thereby improving the high-speed characteristics of the device.

[0065] In the embodiment, the active feedback laser further includes: an N-type electrode 5, which is coplanar with the first ridge waveguide and the at least one second ridge waveguide, and can effectively reduce the propagation path of the current.

[0066] According to the embodiment of the present disclosure, the active feedback laser further includes: a grating structure arranged on both sides of the first ridge waveguide.

[0067] The third aspect of the present disclosure provides a preparation method of an active feedback laser, including:

[0068] Step 1: epitaxially growing a growth structure on a substrate.

[0069] Step two: etching the first ridge waveguide, the at least one second ridge waveguide and the at least one third ridge waveguide on the growth structure.

[0070] The first ridge waveguide is configured to generate a first light beam by injecting a first current.

[0071] The at least one second ridge waveguide is electrically isolated from the first ridge waveguide and is configured to generate at least one second light beam, one second ridge waveguide generating one second light beam by injecting a second current.

[0072] The at least one third ridge waveguide is passively connected to the first ridge waveguide and the at least one second ridge waveguide and is configured to couple the received at least one second light beam into the first ridge waveguide.

[0073] In the first ridge waveguide, the received at least one second light beam forms a photon-photon resonance effect with the first light beam.

[0074] Alternatively,

[0075] The first ridge waveguide and the at least one second ridge waveguide are etched on the growth structure.

[0076] The first ridge waveguide is configured to generate a first light beam by injecting a first current.

[0077] The at least one second ridge waveguide is passively connected to the first ridge waveguide and is configured to generate at least one second light beam and couple the at least one second light beam into the first ridge waveguide so that the at least one second light beam forms a photon-photon resonance effect with the first light beam, one second ridge waveguide generating one second light beam by injecting a second current.

[0078] In the embodiments of the present disclosure, the above-mentioned device can be prepared by one-time epitaxial growth, effectively reducing internal defects of the material, while the preparation method is simple, and the modulation bandwidth is effectively improved.

[0079] Figure 5 The preparation method of the embodiments of the present disclosure is schematically shown.

[0080] Taking an active feedback laser with Figure 1 as an example, as shown in Figure 5 , the present disclosure provides a preparation method of an active feedback laser, comprising:

[0081] Step one: as shown in Figure 5 (1), one-time epitaxial growth is performed on a substrate to form a multi-layer growth structure.

[0082] Step two: as shown in (2), a layer of metal is plated on the growth structure, as shown in (3)-(5), and after the ridge waveguide and the electrode are prepared by coating photoresist and performing photoetching treatment, the excess photoresist is removed.

[0083] Step three: as shown in (6)-(8), coating photoresist, after etching grating structure on both sides of the first ridge waveguide and two third ridge waveguides, removing the excess photoresist.

[0084] Step four: as shown in (9)-(11), coating photoresist, after etching N-type electrode area, removing the excess photoresist.

[0085] Step five: as shown in (12)-(16), coating photoresist, after exposure, evaporating P-type electrode, removing photoresist, and wire bonding.

[0086] Those skilled in the art can understand that the features described in various embodiments and / or claims of the present disclosure can be combined and / or integrated in various combinations, even if such combinations or integrations are not explicitly described in the present disclosure. In particular, the features described in various embodiments and / or claims of the present disclosure can be combined and / or integrated in various combinations without departing from the spirit and teachings of the present disclosure. All such combinations and / or integrations fall within the scope of the present disclosure.

[0087] The above describes embodiments of the present disclosure. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although each embodiment is described above separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, which all fall within the scope of the present disclosure.

Claims

1. An active feedback laser, characterized in that: include: a first ridge waveguide for generating a first light beam by injecting a first current; At least one second ridge waveguide, electrically isolated from the first ridge waveguide, for generating at least one second light beam, wherein the second ridge waveguide generates a second light beam by injecting a second current; at least one third ridge waveguide, passively connected to the first ridge waveguide and the at least one second ridge waveguide, for coupling the received at least one second light beam into the first ridge waveguide; Wherein, in the first ridge waveguide, the received at least one second light beam forms a photon-photon resonance effect with the first light beam; Generating at least one second light beam comprises: Controlling the timing of the corresponding at least one second light beam by regulating the magnitude of the second current injected into the at least one second ridge waveguide; The at least one third ridge waveguide is further used to regulate a first phase of the at least one received second light beam so that the first phase matches a second phase of the first light beam.

2. The active feedback laser according to claim 1, characterized in that: The adjusting the first phase of the at least one received second light beam comprises: A third current is injected into the at least one third ridge waveguide, and the first phase of the at least one second light beam is controlled by controlling the magnitude of the third current.

3. The active feedback laser according to claim 1, characterized in that: Also includes: The N-type electrode is coplanar with the first ridge waveguide, the at least one second ridge waveguide, and the at least one third ridge waveguide.

4. An active feedback laser, characterized in that: include: a first ridge waveguide for generating a first light beam by injecting a first current; as well as At least one second ridge waveguide is passively connected to the first ridge waveguide, and is used to generate at least one second light beam and couple the at least one second light beam into the first ridge waveguide so that the at least one second light beam forms a photon-photon resonance effect with the first light beam; wherein a second ridge waveguide generates a second light beam by injecting a second current.

5. The active feedback laser according to claim 4, characterized in that: Generating at least one second light beam comprises: The timing of the corresponding at least one second light beam is controlled by regulating the magnitude of the second current injected into the at least one second ridge waveguide.

6. The active feedback laser according to claim 4, characterized in that: Also includes: An N-type electrode is coplanar with the first ridge waveguide and the at least one second ridge waveguide.

7. The active feedback laser according to claim 4, characterized in that: Also includes: The grating structure is arranged on both sides of the first ridge waveguide.

8. A method for preparing an active feedback laser, characterized in that: include: preparing a growth structure by epitaxial growth on a substrate; Etching a first ridge waveguide, at least one second ridge waveguide and at least one third ridge waveguide on the growth structure; Wherein, the first ridge waveguide is used to generate a first light beam by injecting a first current; The at least one second ridge waveguide is isolated from the first ridge waveguide and is used to generate at least one second light beam, wherein each second ridge waveguide generates a second light beam by injecting a second current; the generating of the at least one second light beam comprises: controlling the timing of the corresponding at least one second light beam by regulating the magnitude of the second current injected into each of the at least one second ridge waveguides; The at least one third ridge waveguide is passively connected to the first ridge waveguide and the at least one second ridge waveguide, and is used to couple the received at least one second light beam into the first ridge waveguide; the at least one third ridge waveguide is further used to control a first phase of the received at least one second light beam so that the first phase matches a second phase of the first light beam; In the first ridge waveguide, the received at least one second light beam forms a photon-photon resonance effect with the first light beam; or: etching a first ridge waveguide and at least one second ridge waveguide on the growth structure; Wherein, the first ridge waveguide is used to generate a first light beam by injecting a first current; and The at least one second ridge waveguide is passively connected to the first ridge waveguide, and is used to generate at least one second light beam and couple the at least one second light beam into the first ridge waveguide so that the at least one second light beam forms a photon-photon resonance effect with the first light beam; a second ridge waveguide generates a second light beam by injecting a second current.

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