Laser generator and its forming process

Abstract

Embodiments of the present application provide a laser generator and a forming process thereof. The laser generator comprises a laser generating structure, an anti-reflection film, a reflection film, a first electrode and a second electrode. The laser generating structure has a ridge waveguide structure at the top thereof. The anti-reflection film and the reflection film are arranged at the front end surface and the rear end surface of the laser generating structure respectively, and a resonant cavity is formed between the anti-reflection film and the reflection film. The first electrode and the second electrode are arranged at the bottom of the laser generating structure and the top of the ridge waveguide structure respectively, and a forward bias voltage can be applied to the laser generating structure. Since the laser generator is further provided with a current non-injection layer and a third electrode, and the current non-injection layer is spaced apart from the anti-reflection film and the reflection film, the cavity surface of the resonant cavity can be far away from the current non-injection layer. Therefore, while the effect of the third electrode is ensured, the cavity surface defects caused by the current non-injection layer can be effectively avoided, and the stability of the laser generator is significantly improved.

Description

Technical Field

[0001] This application relates to the field of optoelectronic technology, and in particular to a laser generator and its forming process. Background Technology

[0002] Semiconductor laser generators are core devices in optoelectronic technology. With their advantages of small size, high conversion efficiency, and easy integration, they play an irreplaceable role in fields such as optical communication and laser processing.

[0003] However, as the output power of the laser generator increases, the temperature of the laser generator rises sharply, especially in the cavity surface region. Excessive temperature and optical power density can cause melting and recrystallization of the cavity surface, generating numerous lattice defects and causing catastrophic damage to the optical mirrors. This damage is irreversible and therefore severely affects the lifespan and operational stability of the laser generator. To address this, a series of novel structures have been proposed, including aluminum-free quantum well structures to reduce the easy oxidation of aluminum in the active region and the generation of dark line defects, thereby alleviating the cavity surface catastrophic problem. Other approaches utilize large-cavity technology to broaden the optical field distribution and reduce the optical field energy density in the active region and confinement layer. While these methods can solve the problem of excessively high temperatures in the cavity surface region to some extent, they also present significant technical challenges and complex manufacturing processes.

[0004] To reduce the difficulty of laser generator fabrication, existing methods for controlling cavity surface temperature mainly involve fabricating a third electrode at the cavity surface. This third electrode can effectively form a depletion structure, maximally suppressing the heat generated by nonradiative recombination at the cavity surface, thereby improving the thermal stability of the laser generator. However, the third electrode requires the introduction of a current-non-injection layer. This layer, being a polycrystalline dielectric, introduces cavity surface defects and exacerbates nonradiative recombination at the cavity surface, leading to overheating. This results in the laser generator being prone to cracking and detachment during cleavage, increasing photon absorption loss at the cavity surface and exacerbating the overheating problem caused by nonradiative recombination, severely impacting the effectiveness of the third electrode. Summary of the Invention

[0005] This application provides a laser generator and its forming process. By keeping the current non-injection layer away from the cavity surface, the compatibility of the cleavage process is ensured, thereby improving the reliability of the laser generator and solving the technical problem that cavity surface defects caused by the introduction of the current non-injection layer affect the performance of the third electrode.

[0006] In a first aspect, embodiments of this application provide a laser generator, including:

[0007] A laser generating structure has a front end face and a rear end face, and the top of the laser generating structure has a ridge waveguide structure;

[0008] An antireflective coating is disposed on the front end face of the laser generating structure;

[0009] A reflective film is disposed on the rear end face of the laser generating structure;

[0010] The first electrode is disposed at the bottom of the laser generating structure;

[0011] The second electrode is disposed on the top of the ridge waveguide structure;

[0012] A current-non-injection layer is disposed on the top of the ridge waveguide structure and located on both sides of the second electrode near the antireflection film and the reflective film, and is spaced apart from the antireflection film and the reflective film;

[0013] The third electrode is disposed in the current-non-injection layer.

[0014] In some embodiments, a deposition groove is formed on the top of the ridge waveguide structure. The deposition groove is located on both sides of the second electrode near the antireflection film and the reflective film and is spaced apart from the end face of the ridge waveguide structure. The current non-injection layer is deposited in the deposition groove.

[0015] In some embodiments, the tops of the antireflective coating and the reflective coating extend to the front and rear faces of the ridge waveguide structure, respectively, and a spacer wall is formed between the deposition trench and the antireflective coating and the reflective coating, the spacer wall separating the current non-injection layer, the antireflective coating, and the reflective coating.

[0016] In some embodiments, the front and rear faces of the ridge waveguide structure are provided with a first step, the antireflective film and the reflective film extend to the bottom of the first step, and the current non-injection layer is located on the side of the first step near the second electrode.

[0017] In some embodiments, the top surface of the ridge waveguide structure has a second step, which is located on the side of the first step near the second electrode, and the current non-injection layer is deposited on the second step.

[0018] In some embodiments, the top of the first step extends to the top surface of the ridge waveguide structure and connects with the second step.

[0019] In some embodiments, the laser generating structure further has an upper confinement layer located at the bottom of the ridge waveguide structure, the bottom of the first step extending to the upper confinement layer.

[0020] Secondly, a laser generator forming process includes the following steps:

[0021] An epitaxial structure with a ridge waveguide layer is formed by epitaxial growth;

[0022] A laser generating structure with a ridge waveguide structure is obtained by etching the ridge waveguide layer of the epitaxial structure.

[0023] A current-non-injection layer is deposited on top of the ridge waveguide structure;

[0024] An antireflective film spaced apart from the current non-injection layer is formed on the front end surface of the laser generating structure, and a reflective film spaced apart from the current non-injection layer is formed on the rear end surface of the laser generating structure.

[0025] A first electrode is formed on the bottom of the laser generating structure, a second electrode is formed on the top of the ridge waveguide structure, and a third electrode is formed on the current non-injection layer.

[0026] In some embodiments, the laser generator forming process further includes: etching deposition trenches spaced apart from the end faces of the ridge waveguide structure on the top of the ridge waveguide structure before depositing a current-injection-free layer on the top of the ridge waveguide structure;

[0027] The deposition of a current-non-injection layer on top of the ridge waveguide structure includes:

[0028] A current-free layer is deposited in the deposition tank.

[0029] In some embodiments, the laser generator forming process further includes: before depositing a current-injection-free layer on the top of the ridge waveguide structure, etching a first step extending to the top surface of the ridge waveguide structure on the front and rear faces of the ridge waveguide structure, and etching a second step that connects to the first step on the top surface of the ridge waveguide structure.

[0030] The deposition of a current-non-injection layer on top of the ridge waveguide structure includes:

[0031] A current-injection-free layer is deposited in the second step.

[0032] The laser generator provided in this application includes a laser generating structure, an anti-reflection film, a reflective film, a first electrode, and a second electrode. The top of the laser generating structure has a ridge waveguide structure, which can confine the light field and thus limit the propagation range of the laser. The anti-reflection film and the reflective film are respectively disposed on the front and rear faces of the laser generating structure, and a resonant cavity is formed between the anti-reflection film and the reflective film. The first electrode and the second electrode are respectively disposed on the bottom of the laser generating structure and the top of the ridge waveguide structure, and a positive bias voltage can be applied to the laser generating structure to generate a light field. The light field is enhanced in the resonant cavity and finally emitted from the anti-reflection film to form a high-intensity laser.

[0033] Since the laser generator also has a current non-injection layer and a third electrode, the current non-injection layer is located on the top of the ridge waveguide structure and on both sides of the second electrode near the antireflection film and the reflection film. The third electrode is located on the current non-injection layer. The third electrode and the current non-injection layer can significantly reduce the heat generated by the non-radiative recombination of the cavity surface of the resonant cavity, thereby improving the thermal stability of the laser generator. Moreover, since the current non-injection layer is spaced apart from the antireflection film and the reflection film, it can be far away from the cavity surface of the resonant cavity. Thus, while ensuring the effect of the third electrode, it can effectively avoid the current non-injection layer from introducing cavity surface defects, and significantly improve the stability of the laser generator. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0035] Figure 1 A schematic diagram of the structure of the laser generator with a current-free injection layer deposited in the deposition tank, as provided in this application;

[0036] Figure 2 A schematic diagram of the structure of the laser generator with a current-free injection layer deposited on the second step, as provided in this application;

[0037] Figure 3 The process flow diagram of the laser generator provided in this application;

[0038] Figure 4 A schematic diagram of the structure formed by process step A1 provided in this application;

[0039] Figure 5 A schematic diagram of the structure formed by process step A2 provided in this application;

[0040] Figure 6 A schematic diagram of the structure formed by process step A3 provided in this application;

[0041] Figure 7 A schematic diagram of the structure formed by process step A4 provided in this application;

[0042] Figure 8 A schematic diagram of the structure formed by process step A5 provided in this application;

[0043] Figure 9 A schematic diagram of the structure formed by process step A6 provided in this application;

[0044] Figure 10 A schematic diagram of the structure formed by process step A7 provided in this application;

[0045] Figure 11 A schematic diagram of the structure formed by process step A9 provided in this application;

[0046] Figure 12 A schematic diagram of the structure formed by process step B1 provided in this application;

[0047] Figure 13 A schematic diagram of the structure formed by process step B2 provided in this application;

[0048] Figure 14 A schematic diagram of the structure formed by process step B3 provided in this application;

[0049] Figure 15 A schematic diagram of the structure formed by process step B4 provided in this application;

[0050] Figure 16 A schematic diagram of the structure formed by process step B5 provided in this application;

[0051] Figure 17 A schematic diagram of the structure formed by process step B6 provided in this application;

[0052] Figure 18 A schematic diagram of the structure formed by process step B7 provided in this application;

[0053] Figure 19 A schematic diagram of the structure formed by process step B8 provided in this application;

[0054] Figure 20 A schematic diagram of the structure formed by process step B10 provided in this application.

[0055] Figure label:

[0056] 10—Laser generating structure; 10a—Front end face; 10b—Rear end face; 11—Substrate layer; 12—Lower confinement layer; 13—Lower waveguide layer; 14—Quantum well active layer; 15—Upper waveguide layer; 16—Upper confinement layer; 17—Ridge waveguide structure; 171—Deposition trench; 172—Second step; 173—First step;

[0057] 20—Antireflection coating; 30—Reflective coating; 40—Second electrode; 50—First electrode; 60—Current non-injection layer; 70—Third electrode; 80—Epipolar structure; 81—Ridge waveguide layer; a—First mask; b—Second mask.

[0058] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0059] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0060] As the output power of a laser generator increases, the cavity surface temperature of the semiconductor laser generator rises sharply, causing melting and recrystallization at the cavity surface, resulting in numerous lattice defects. To suppress the cavity surface temperature of high-power semiconductor laser generators, related technologies primarily involve fabricating a third electrode at the cavity surface. This third electrode can effectively form a depletion structure, maximizing the suppression of heat generated by non-radiative recrystallization at the cavity surface. However, this third electrode requires the introduction of a current-non-injection layer. Introducing this layer necessitates etching the cavity surface of the laser generator structure, followed by deposition. During the etching process, cavity surface etching defects are inevitably introduced, leading to overheating. Furthermore, the deposited current-non-injection layer is located at the cavity surface. Since this layer is a polycrystalline material, it lacks the same cleavage plane as the cavity surface of the laser generator structure. Therefore, during the cleavage process at the cavity surface of the laser generator structure, the current-non-injection layer is prone to breakage and detachment.

[0061] Based on the above scenarios, it can be seen that the technical means of suppressing the cavity surface temperature by introducing a third electrode in the relevant technologies has a technical problem: cavity surface defects caused by the non-injection layer of the current introduced by the third electrode affect the performance of the third electrode.

[0062] To address the technical problem of cavity surface defects caused by the non-injected current layer affecting the performance of the third electrode, the laser generator and its forming process provided in this application solve the technical problem of cavity surface defects caused by the non-injected current layer by moving the non-injected current layer away from the cavity surface, thereby avoiding cavity surface defects and ensuring the compatibility of the cleavage process.

[0063] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0064] To better understand this application, the following is combined with... Figures 1 to 20 The technical solution of this application is described in detail below:

[0065] The laser generator provided in the embodiments of this application, such as Figure 1 and Figure 2 As shown, the laser generating structure 10 is used to generate laser light through an electric current. The laser generating structure 10 has a front face 10a and a rear face 10b, which are perpendicular to the photon propagation direction within the laser generating structure 10. The laser generating structure 10 includes an active region and a waveguide structure. The active region is the core area for photon generation and amplification; by injecting current, electrons and holes recombine here to generate photons. The waveguide structure is used to limit the propagation of photons in the lateral direction, reduce light leakage, and improve beam quality and output power.

[0066] The laser generator provided in this embodiment further includes an antireflection coating 20, a reflective coating 30, a first electrode 50, a second electrode 40, a current non-injection layer 60, and a third electrode 70. The laser generating structure 10 has a ridge waveguide structure 17 at its top. The antireflection coating 20 is disposed on the front end face 10a of the laser generating structure 10, the reflective coating 30 is disposed on the rear end face 10b of the laser generating structure 10, the first electrode 50 is disposed at the bottom of the laser generating structure 10, the second electrode 40 is disposed on the top of the ridge waveguide structure 17, the current non-injection layer 60 is disposed on the top of the ridge waveguide structure 17 and located on both sides of the second electrode 40 near the antireflection coating 20 and the reflective coating 30, and is spaced apart from the antireflection coating 20 and the reflective coating 30, and the third electrode 70 is disposed on the current non-injection layer 60.

[0067] Specifically, the laser generator comprises a laser generating structure 10, an anti-reflection film 20, a reflective film 30, a first electrode 50, and a second electrode 40. The top of the laser generating structure 10 has a ridge waveguide structure 17, which can limit the light field and thus limit the propagation range of the laser. The anti-reflection film 20 and the reflective film 30 are respectively disposed on the front end face 10a and the rear end face 10b of the laser generating structure 10, forming a resonant cavity between the anti-reflection film 20 and the reflective film 30. The front end face 10a and the rear end face 10b of the laser generating structure 10 form the cavity surface of the resonant cavity, and the front and rear ends of the laser generating structure 10 are the cavity surface ends of the resonant cavity.

[0068] The first electrode 50 and the second electrode 40 are respectively disposed at the bottom of the laser generating structure 10 and the top of the ridge waveguide structure 17. A forward bias voltage can be applied to the laser generating structure 10. After current is passed through the active region of the laser generating structure 10, electrons and holes recombine in the active region to generate photons. The photons oscillate repeatedly in the resonant cavity and are continuously amplified to form a light field. The light field is enhanced in the resonant cavity and finally emitted from the antireflection film 20 to form a high-intensity laser.

[0069] Since the laser generator is also provided with a current non-injection layer 60 and a third electrode 70, the current non-injection layer 60 is disposed on the top of the ridge waveguide structure 17 and located on both sides of the second electrode 40 near the antireflection film 20 and the reflective film 30. The third electrode 70 is disposed on the current non-injection layer 60. The third electrode 70 applies a positive bias voltage to the current non-injection layer 60 to block the injection of charge carriers into the cavity surface of the resonant cavity, thereby reducing the charge carrier concentration at the cavity surface, decreasing non-radiative recombination, and reducing the heat generation at the cavity surface. This achieves the effect of reducing the heat generated by non-radiative recombination at the cavity surface of the resonant cavity, thereby improving the thermal stability of the laser generator.

[0070] In this embodiment, by spacing the non-injection layer 60 from the antireflection film 20 and the reflective film 30, the non-injection layer 60 is positioned away from the cavity surface of the resonant cavity. Therefore, during the deposition of the non-injection layer 60, it is unnecessary to etch the cavity surface end of the resonant cavity, thus avoiding etching defects at the cavity surface end and the introduction of cavity surface defects. Furthermore, the non-injection layer 60 does not act as a cleavage surface, preventing cleavage surface breakage and defects in the cleavage surface structure. Therefore, while ensuring the effectiveness of the third electrode 70, it effectively avoids the introduction of cavity surface defects by the non-injection layer 60, significantly improving the stability of the laser generator.

[0071] In some embodiments, such as Figure 1 and Figure 2 As shown, the laser generating structure 10 includes a substrate layer 11, a lower confinement layer 12, a lower waveguide layer 13, a quantum well active layer 14, an upper waveguide layer 15, an upper confinement layer 16, and a ridge waveguide structure 17 arranged in sequence.

[0072] Specifically, substrate 11 serves as the foundation of the entire laser generating structure 10. The quantum well active layer 14 effectively traps electrons and holes, improving carrier recombination efficiency and thus generating more photons. It is the core region for photon generation, where electrons and holes recombine to produce photons. The lower confinement layer 12 restricts the vertical expansion of photons and carriers, ensuring their concentration within the quantum well active layer 14. The lower waveguide layer 13 has a lower refractive index, creating a refractive index difference with the lower confinement layer 12 to further guide photon propagation within the quantum well active layer 14 and reduce light leakage. The upper waveguide layer 15, similar to the lower waveguide layer 13, also has a lower refractive index, creating a refractive index difference with the upper confinement layer 16 to further guide photon propagation and reduce light leakage. The upper confinement layer 16 has a higher refractive index, restricting the vertical expansion of photons and carriers and ensuring their concentration within the quantum well active layer 14.

[0073] Understandably, the materials and dimensions of the substrate layer 11, lower confinement layer 12, lower waveguide layer 13, quantum well active layer 14, upper waveguide layer 15, upper confinement layer 16, and ridge waveguide structure 17 can be adapted to actual needs.

[0074] The substrate 11 needs to have good crystal quality and low defect density. In some embodiments, the substrate 11 is GaN (gallium nitride) or GaAs (gallium arsenide) with a thickness between 200 nm and 3000 nm. For example, the thickness of the substrate 11 can be any value between 200 nm, 3000 nm, and 200-3000 nm, such as 500 nm, 1000 nm, and 2000 nm.

[0075] In some embodiments, the material of the lower confinement layer 12 can be AlInGaN (aluminum indium gallium nitride) or AlGaAs (aluminum gallium arsenide), and its thickness is between 0.3 and 1 μm. For example, the thickness of the lower confinement layer 12 can be any value between 0.3 μm, 1 μm, and 0.3-1 μm, such as 0.5 μm, 0.7 μm, and 0.9 μm.

[0076] In some embodiments, the lower waveguide layer 13 is made of AlInGaN (aluminum indium gallium nitride) or AlGaAs (aluminum gallium arsenide), and its thickness is between 0.1 and 3 μm. For example, the thickness of the lower waveguide layer 13 can be any value between 0.1 μm, 3 μm, and 0.1-3 μm, such as 0.2 μm, 2 μm, and 2.5 μm.

[0077] In some embodiments, the active quantum well layer 14 is made of alternating AlInGaN (aluminum indium gallium nitride) well layers and AlInGaN (aluminum indium gallium nitride) barrier layers, or alternating InGaAs (indium gallium arsenide) well layers and AlGaAs (aluminum gallium arsenide) barrier layers, with a thickness between 0.02 and 0.5 μm. For example, the thickness of the active quantum well layer 14 can be any value between 0.02 μm, 0.5 μm, and 0.02-0.5 μm, such as 0.1 μm, 0.25 μm, and 0.4 μm.

[0078] In some embodiments, the upper waveguide layer 15 is made of AlInGaN (aluminum indium gallium nitride) or AlGaAs (aluminum gallium arsenide), and its thickness is between 0.1 and 3 μm. For example, the thickness of the lower waveguide layer 13 can be any value between 0.1 μm, 3 μm, and 0.1-3 μm, such as 0.21 μm, 1.2 μm, and 2.5 μm.

[0079] In some embodiments, the upper confinement layer 16 is made of AlInGaN (aluminum indium gallium nitride) or AlGaAs (aluminum gallium arsenide), and its thickness is between 0.3 and 1 μm. For example, the thickness of the upper confinement layer 16 can be any value between 0.3 μm, 1 μm, and 0.3-1 μm, such as 0.4 μm, 0.6 μm, and 0.9 μm.

[0080] In this embodiment, the ridge waveguide structure 17 restricts the expansion of the light field in the lateral direction, reduces light leakage, and improves the output quality and output power of the beam. In some embodiments, the material of the ridge waveguide structure 17 is AlInGaN (aluminum indium gallium nitride) or AlGaAs (aluminum gallium arsenide), and the thickness is between 250 nm and 350 nm. For example, the thickness of the ridge waveguide structure 17 can be any value between 250 nm, 350 nm, and 250 nm-350 nm, such as 208 nm and 300 nm.

[0081] In some embodiments, the laser generating structure 10 further includes a passivation layer (not shown in the figure). The passivation layer is disposed on the periphery of the ridge waveguide structure 17. The passivation layer can isolate substances such as water vapor, oxygen, and corrosive gases (such as hydrogen sulfide). The material and size of the passivation layer can be adapted according to actual needs, mainly to prevent the surface of the ridge waveguide structure 17 from being mechanically damaged, scratched, or contaminated. In some embodiments, the material of the passivation layer is silicon dioxide (SiO2), silicon nitride (Si3N4), and aluminum oxide (Al2O3), etc., and the thickness of the passivation layer is between 10 nm and 500 nm. For example, the thickness of the passivation layer can be any value between 10 nm, 500 nm, and 100 nm-500 nm, such as 100 nm and 400 nm.

[0082] Understandably, the antireflection coating 20 is mainly used to reduce surface reflection, improve transmittance, and reduce cavity surface loss. It can be made of materials such as silicon dioxide (SiO2), aluminum oxide (Al2O3), or titanium dioxide (TiO2). Its transmittance and size can be adapted to the size of the laser generating structure 10 and actual needs, as long as it can provide laser emission and form a gap with the current non-injection layer 60. In some embodiments, the transmittance of the antireflection coating 20 is less than 10%.

[0083] Understandably, the reflective film 30 is mainly used to form a high-reflectivity mirror, realize optical feedback, and maintain laser oscillation. It is a multilayer dielectric film, which can be made of materials such as a combination of silicon dioxide (SiO2) and titanium dioxide (TiO2), a combination of silicon dioxide (SiO2) and tantalum pentoxide (Ta2O5), or a combination of silicon dioxide (SiO2) and hafnium dioxide (HfO2). Its transmittance and size can be adapted to the size of the laser generating structure 10 and actual needs, as long as it can efficiently reflect photons and form a gap with the current non-injection layer 60. In some embodiments, the transmittance of the antireflective film 20 is above 50%.

[0084] In this embodiment, the first electrode 50 and the second electrode 40 are the core structures for current injection. The first electrode 50 and the second electrode 40 are respectively connected to the P-type region and the N-type region of the chip to realize carrier injection so that the laser generating structure can form a laser.

[0085] In some embodiments, the first electrode 50 is a negative electrode plate, which is the outlet of current, and can be made of metals such as titanium (Ti), aluminum (Al) or gold (Au). The second electrode 40 is a positive electrode plate, which is the injection point of current, and can be made of metals such as titanium (Ti), platinum (Pt) or gold (Au).

[0086] Understandably, the current-non-injection layer 60 is an insulating medium, which can be one of alumina (Al2O3), silicon nitride (SiN), or silicon dioxide (SiO2). The current-non-injection layer 60 is formed on the top surface of the ridge waveguide structure 17 by a deposition process, with its surface flush with the top surface of the ridge waveguide structure 17, and its thickness should be less than the thickness of the ridge waveguide structure 17. In some embodiments, the thickness of the current-non-injection layer 60 ranges from 10 nm to 50 nm; for example, the thickness of the current-non-injection layer 60 can be 10 nm, 20 nm, 25 nm, and 50 nm, etc.

[0087] To create a gap between the current non-injection layer 60 and the antireflection film 20 and the reflective film 30, in some embodiments, such as Figure 1 As shown, a deposition trench 171 is formed on the top of the ridge waveguide structure 17. The deposition trench 171 is located on both sides of the second electrode 40 near the antireflection film 20 and the reflective film 30 and is spaced apart from the end face of the ridge waveguide structure 17. The current non-injection layer 60 is deposited in the deposition trench 171. Specifically, the non-injected current layer 60 is formed on the top of the ridge waveguide structure 17 by deposition in the deposition tank 171. Since the deposition tank 171 is located on the top surface of the ridge waveguide structure 17 and is spaced apart from the end face of the ridge waveguide structure 17, only the top surface of the ridge waveguide structure 17 needs to be etched during the deposition tank 171 formation process. The end face of the ridge waveguide structure 17 will not be etched. As part of the cavity surface, the end face will not form defects due to the etching of the deposition tank 171. Therefore, the deposition of the non-injected current layer 60 will not cause cavity surface defects. Furthermore, the non-injected current layer 60 will be far away from the end face of the ridge waveguide structure 17, thereby making the end face of the non-injected current layer 60 far away from the cleavage surface, thus preventing cleavage surface defects caused by the cleavage process.

[0088] To reduce the molding difficulty of the antireflective coating 20 and the reflective coating 30, and to increase the power of the laser generator, in some embodiments, such as Figure 1As shown, the tops of the antireflection coating 20 and the reflective coating 30 extend to the front and rear faces of the ridge waveguide structure 17, respectively. A spacer wall is formed between the deposition trench 171 and the antireflection coating 20 and the reflective coating 30, separating the current non-injection layer 60, the antireflection coating 20, and the reflective coating 30. Specifically, since the current injection layer is far from the front and rear faces of the ridge waveguide structure 17, extending the antireflection coating 20 and the reflective coating 30 to the front and rear faces of the ridge waveguide structure 17 ensures the integrity of the cavity surface and improves the power of the laser generator. The antireflection coating 20 and the reflective coating 30 can always maintain a distance from the current non-injection layer 60 through the spacer wall.

[0089] To create a gap between the current non-injection layer 60 and the antireflection film 20 and the reflective film 30, in some embodiments, such as Figure 2 As shown, the front and rear faces of the ridge waveguide structure 17 have first steps 173. The antireflective coating 20 and the reflective coating 30 extend to the bottom of the first step 173, and the current non-injection layer 60 is located on the side of the first step 173 near the second electrode 40. Specifically, the front face 10a and the rear face 10b of the laser generating structure 10 only serve as the cavity surface and cleavage surface below the first step 173. The current non-injection layer 60 is deposited on the top surface of the ridge waveguide structure 17, thus forming a gap with the cavity surface and cleavage surface through the first step 173. This allows the current non-injection layer 60 to be far away from the cavity surface and cleavage surface, thereby avoiding cavity surface defects caused by the deposition of the current non-injection layer 60 and the collapse of the cleavage surface during the cleavage process.

[0090] In some embodiments, such as Figure 2 As shown, a second step 172 is formed on the top surface of the ridge waveguide structure 17. The second step 172 is located on the side of the first step 173 near the second electrode 40, and a current-non-injection layer 60 is deposited on the second step 172. Specifically, the second step 172 allows for the deposition of the current-non-injection layer 60, forming a current-non-injection layer 60 away from the cavity surface on the top of the ridge waveguide structure 17. Since the second step 172 is spaced from the cavity through the first step 173, cavity surface defects are not caused during the etching process of the second step 172.

[0091] In some embodiments, such as Figure 2 As shown, the top of the first step 173 extends to the top surface of the ridge waveguide structure 17 and connects with the second step 172. Specifically, since the first step 173 and the second step 172 are connected, during the etching process of the first step 173 and the second step 172, the second step 172 extending to the end face of the ridge waveguide structure 17 can be etched first, and then the first step 173 can be formed by etching downwards from the edge of the second step 172, which effectively simplifies the etching process of the first step 173 and the second step 172.

[0092] In some embodiments, such as Figure 2As shown, the laser generating structure 10 also has an upper confinement layer 16 located at the bottom of the ridge waveguide structure 17, and the bottom of the first step 173 extends to the upper confinement layer 16. Specifically, the first step 173 extends to the bottom of the upper confinement layer 16, such that the front and rear faces of the substrate layer 11, lower confinement layer 12, lower waveguide layer 13, quantum well active layer 14, and upper waveguide layer 15 located below the upper confinement layer 16 will form cavity surfaces, while the front and rear faces of the ridge waveguide structure 17 will not form cavity surfaces, thereby reducing the risk of end-face damage to the ridge waveguide structure 17, reducing cavity surface defects, and thus suppressing cavity surface overheating.

[0093] In this embodiment, the third electrode 70 is configured as a positive plate. A positive voltage is applied to the third electrode 70 to repel charge carriers away from the cavity surface, thereby reducing the heat generated by nonradiative recombination and light absorption at the cavity surface. The third electrode 70 can be made of metals such as titanium (Ti), aluminum (Al), or gold (Au).

[0094] This application also provides a laser generator forming process, such as... Figure 3 As shown, it includes the following steps:

[0095] S100: An epitaxial structure 80 with a ridge waveguide layer 81 is formed by epitaxial growth;

[0096] S200: A laser generating structure 10 with a ridge waveguide structure 17 is obtained by etching the ridge waveguide layer 81 of the epitaxial structure 80.

[0097] S300: A current-non-injection layer 60 is deposited on top of the ridge waveguide structure 17;

[0098] S400: An antireflective film 20 is formed on the front end face 10a of the laser generating structure 10, spaced apart from the current non-injection layer 60, and a reflective film 30 is formed on the rear end face 10b of the laser generating structure 10, spaced apart from the current non-injection layer 60.

[0099] S500: A first electrode 50 is formed on the bottom of the laser generating structure 10, a second electrode 40 is formed on the top of the ridge waveguide structure 17, and a third electrode 70 is formed on the current non-injection layer 60.

[0100] Specifically, through the above process, a current non-injection layer 60 can be formed that is spaced apart from the antireflection film 20 and the reflective film 30, which can effectively avoid the introduction of cavity surface defects by the current non-injection layer 60 and significantly improve the stability of the laser generator.

[0101] In some embodiments, the laser generator forming process further includes: etching deposition trenches 171 spaced apart from the end faces of the ridge waveguide structure 17 on the top of the ridge waveguide structure 17 before depositing a current non-injection layer 60 on the top of the ridge waveguide structure 17.

[0102] A current-injection-free layer 60 is deposited on top of the ridge waveguide structure 17, comprising:

[0103] A current-injected non-injection layer 60 is deposited in deposition tank 171.

[0104] Specifically, through the above process, a current-injected layer 60 far from the cavity surface can be deposited through the deposition tank 171.

[0105] In some embodiments, the laser generator forming process further includes: before depositing a current non-injection layer 60 on the top of the ridge waveguide structure 17, etching a first step 173 extending to the top surface of the ridge waveguide structure 17 on the front and rear faces of the ridge waveguide structure 17, and etching a second step 172 connected to the first step 173 on the top surface of the ridge waveguide structure 17.

[0106] A current-injection-free layer 60 is deposited on top of the ridge waveguide structure 17, comprising:

[0107] In the second step 172, a current-free non-injection layer 60 is deposited.

[0108] Specifically, through the above process, a current-injected layer 60 far from the cavity surface can be deposited through the second step 172.

[0109] In this embodiment, the laser generator forming process includes process A, which deposits a current non-injection layer 60 through a deposition tank 171, and process B, which deposits a current non-injection layer 60 through a second step 172.

[0110] Process A, which involves depositing a current-non-injected layer 60 through deposition tank 171, includes:

[0111] A1: As Figure 4 As shown, an epitaxial structure 80 with a ridge waveguide layer 81 is formed by epitaxial growth. The epitaxial structure 80 with a ridge waveguide layer 81 is formed by epitaxial growth including: placing the substrate in the growth chamber of an MOCVD (Metal-Organic Chemical Vapor Deposition) device, and sequentially growing a lower confinement layer 12, a lower waveguide layer 13, a quantum well active layer 14, an upper waveguide layer 15, an upper confinement layer 16 and a ridge waveguide layer 81.

[0112] A2: As Figure 5 As shown, a laser generating structure 10 with a ridge waveguide structure 17 is obtained by etching the ridge waveguide layer 81 of the epitaxial structure 80. The etching process includes photolithography and dry etching.

[0113] A3: As Figure 6 As shown, photoresist is applied to the top of the ridge waveguide structure 17 as a first mask a. The first mask a exposes the etched portion of the deposition tank 171. The etched portion is spaced apart from the ridge waveguide structure 17 and the front and rear end faces.

[0114] A4: As Figure 7 As shown, a deposition tank 171 is etched into the etched area by dry etching.

[0115] A5: As Figure 8 As shown, a current-injected layer 60 matching the step depth is deposited on the deposition tank 171.

[0116] A6: As Figure 9 As shown, remove the first mask a.

[0117] A7: As Figure 10 As shown, the first electrode 50, the second electrode 40, and the third electrode 70 are fabricated using photolithography and vapor deposition processes.

[0118] A8: Deposit a passivation layer, and remove the passivation layer on the first electrode 50, the second electrode 40 and the third electrode 70 and the front end face 10a and the rear end face 10b of the laser generating structure 10 by photolithography and using an etchant to expose the electrical injection window.

[0119] A9: As Figure 11 As shown, a reflective film 30 is deposited on the rear end face 10b of the laser generating structure 10 by chemical plating, electroplating and other methods, and an antireflection film 20 is deposited on the front end face 10a of the laser generating structure 10, so as to obtain a laser generator with a current non-injection layer 60 deposited on the deposition tank 171.

[0120] Process B, which involves depositing a current-non-injected layer 60 through deposition tank 171, includes:

[0121] B1: As Figure 12 As shown, an epitaxial structure 80 with a ridge waveguide layer 81 is formed by epitaxial growth. The epitaxial structure 80 with a ridge waveguide layer 81 is formed by epitaxial growth including: placing the substrate in the growth chamber of an MOCVD (Metal-Organic Chemical Vapor Deposition) device, and sequentially growing a lower confinement layer 12, a lower waveguide layer 13, a quantum well active layer 14, an upper waveguide layer 15, an upper confinement layer 16 and a ridge waveguide layer 81.

[0122] B2: such as Figure 13 As shown, a laser generating structure 10 with a ridge waveguide structure 17 is obtained by etching the ridge waveguide layer 81 of the epitaxial structure 80. The etching process includes photolithography and dry etching.

[0123] B3: such as Figure 14 As shown, photoresist is applied to the top of the ridge waveguide structure 17 as a second mask b. The second mask b exposes the etched portion of the first step 173, and the etched portion is connected to the front and rear end faces of the ridge waveguide structure 17.

[0124] B4: such as Figure 15 As shown, a second step 172 is etched into the etched area by dry etching.

[0125] B5: such as Figure 16 As shown, the first step 173 extends to the bottom of the upper confinement layer 16 by dry etching of the second step 172.

[0126] B6: For example Figure 17 As shown, a current-injected layer 60 matching the step depth is deposited on the second step 172.

[0127] B7: As Figure 18 As shown, remove the second mask b.

[0128] B8: As Figure 19 As shown, the first electrode 50, the second electrode 40, and the third electrode 70 are fabricated using photolithography and vapor deposition processes.

[0129] B9: Deposit a passivation layer and remove the passivation layer on the first electrode 50, the second electrode 40 and the third electrode 70 and the front end face 10a and the rear end face 10b of the laser generating structure 10 by photolithography and using an etchant to expose the electrical injection window.

[0130] B10: such as Figure 20 As shown, a reflective film 30 is deposited on the rear end face 10b of the laser generating structure 10 by chemical plating, electroplating and other methods, and an antireflection film 20 is deposited on the front end face 10a of the laser generating structure 10, so as to obtain a laser generator with a current non-injection layer 60 deposited on the second step 172.

[0131] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A laser generator, characterized in that, include: A laser generating structure has a front end face and a rear end face, and the top of the laser generating structure has a ridge waveguide structure; An antireflective coating is disposed on the front end face of the laser generating structure; A reflective film is disposed on the rear end face of the laser generating structure; The first electrode is disposed at the bottom of the laser generating structure; The second electrode is disposed on the top of the ridge waveguide structure; A current-non-injection layer is disposed on the top of the ridge waveguide structure and located on both sides of the second electrode near the antireflection film and the reflective film, and is spaced apart from the antireflection film and the reflective film; The third electrode is disposed in the current-non-injection layer.

2. The laser generator according to claim 1, characterized in that, A deposition groove is formed on the top of the ridge waveguide structure. The deposition groove is located on both sides of the second electrode near the antireflection film and the reflection film and is spaced apart from the end face of the ridge waveguide structure. The current non-injection layer is deposited in the deposition groove.

3. The laser generator according to claim 2, characterized in that, The tops of the antireflective coating and the reflective coating extend to the front and rear faces of the ridge waveguide structure, respectively. A spacer wall is formed between the deposition trench and the antireflective coating and the reflective coating, and the spacer wall separates the current non-injection layer, the antireflective coating, and the reflective coating.

4. The laser generator according to claim 1, characterized in that, The ridge waveguide structure has a first step on its front and rear faces, the antireflective coating and the reflective coating extend to the bottom of the first step, and the current non-injection layer is located on the side of the first step near the second electrode.

5. The laser generator according to claim 4, characterized in that, The top surface of the ridge waveguide structure has a second step, which is located on the side of the first step near the second electrode, and the current non-injection layer is deposited on the second step.

6. The laser generator according to claim 5, characterized in that, The top of the first step extends to the top surface of the ridge waveguide structure and connects with the second step.

7. The laser generator according to claim 4, characterized in that, The laser generating structure also has an upper confinement layer located at the bottom of the ridge waveguide structure, and the bottom of the first step extends to the upper confinement layer.

8. A laser generator forming process, characterized in that, Includes the following steps: An epitaxial structure with a ridge waveguide layer is formed by epitaxial growth; A laser generating structure with a ridge waveguide structure is obtained by etching the ridge waveguide layer of the epitaxial structure. A current-non-injection layer is deposited on top of the ridge waveguide structure; An antireflective film spaced apart from the current non-injection layer is formed on the front end surface of the laser generating structure, and a reflective film spaced apart from the current non-injection layer is formed on the rear end surface of the laser generating structure. A first electrode is formed on the bottom of the laser generating structure, a second electrode is formed on the top of the ridge waveguide structure, and a third electrode is formed on the current non-injection layer.

9. The laser generator forming process according to claim 8, characterized in that, It also includes: etching deposition trenches spaced apart from the end faces of the ridge waveguide structure on the top of the ridge waveguide structure before depositing a current-injection-free layer on the top of the ridge waveguide structure; A current-non-injection layer is deposited on top of the ridge waveguide structure, comprising: A current-free layer is deposited in the deposition tank.

10. The laser generator forming process according to claim 8, characterized in that, Also includes: Before depositing a current-injected non-injection layer on the top of the ridge waveguide structure, a first step extending to the top surface of the ridge waveguide structure is etched on the front and rear faces of the ridge waveguide structure, and a second step connecting with the first step is etched on the top surface of the ridge waveguide structure. A current-non-injection layer is deposited on top of the ridge waveguide structure, comprising: A current-injection-free layer is deposited in the second step.

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