Edge-emitting tunable semiconductor laser and optical device

Abstract

An edge-emitting tunable semiconductor laser and optical device provided in an embodiment of the present invention include an emitting component, a piezoelectric component, an external cavity mirror and a chip rear cavity mirror, wherein the piezoelectric component has a light-through hole, the edge-emitting component includes an active area, the chip rear cavity mirror is attached to the side of the edge-emitting component and contacts with one end of the active area, the other side of the edge-emitting component is attached to the piezoelectric component, the other side of the edge-emitting component has a light-emitting cavity surface, the light-emitting cavity surface has an optical anti-reflection film, the external cavity mirror is attached to the opposite surface of the piezoelectric component where the edge-reflecting component is installed, the chip rear cavity mirror, the active area, the light-through hole and the external cavity mirror constitute an optical resonant cavity, the piezoelectric component generates a mechanical expansion effect under the drive of an external modulation voltage signal, the optical resonant cavity length is changed, the laser working wavelength is tuned, and a higher laser output power is achieved, the laser working wavelength can be broadened to the short-wave infrared band, which is conducive to expanding more application scenarios.

Description

Technical Field

[0001] The invention relates to the field of laser semiconductors, and in particular to an edge-emitting tunable semiconductor laser and optical equipment. Background Art

[0002] Tunable semiconductor lasers have the advantages of small size, light weight, and low energy consumption, and are widely used in laser communication, laser sensing and other fields. At present, the more mature tunable semiconductor laser products can be divided into two categories from the perspective of technology type: the first category is traditional chip-level lasers such as DFB lasers, DBR lasers and VCSEL lasers. This type of laser has the advantages of single-chip operation, high reliability and stability, and relies on tuning the drive current or operating temperature to achieve wavelength tuning. The main disadvantage is that the wavelength tuning range is very small, usually only a few nm level; the second category is tunable semiconductor lasers based on external cavities, which rely on tuning the external cavity length or external optical elements with wavelength selectivity (such as diffraction gratings) to achieve wavelength tuning. This type of laser has outstanding advantages such as narrow spectral linewidth and large wavelength tuning range. The main disadvantage is that due to the addition of a macroscopic electromechanical system outside the chip, the reliability and stability are poor and it is easily disturbed by external environmental factors.

[0003] In recent years, products that combine the advantages of the above two types of tunable semiconductor lasers have been launched. The most representative one is the VCSEL (Vertical-Cavity Surface-Emitting Laser) tunable semiconductor laser with a monolithic integrated MEMS (Micro-Electro-Mechanical System) external cavity structure. On the one hand, it has the characteristics of a large wavelength tuning range brought by the external cavity structure, and on the other hand, it also has the characteristics of high reliability and stability brought by chip-level devices, so it has great development potential. However, the shortcomings of this commercial solution are also obvious: on the one hand, due to the use of VCSEL structure as the construction basis, although a multi-quantum well active area is used, in order to ensure good output beam characteristics, the active area working area must be limited to a smaller aperture, so the laser output power is low; on the other hand, due to the use of GaAs-based active area materials, the laser working wavelength is limited to the near-infrared band (0.7μm-1.1μm), which limits the application scenarios.

[0004] The above-mentioned VCSEL tunable semiconductor laser commercial solution with MEMS external cavity structure has excellent characteristics such as single-frequency output and large wavelength tuning range, and because of the monolithic integrated structure, the reliability and stability are also high. However, the shortcomings of this commercial solution are also obvious: on the one hand, due to the use of VCSEL structure as the construction basis, although a multi-quantum well active area is used, in order to ensure the single-frequency output characteristics, the active area working area must be kept very small, so the laser output power is very low; on the other hand, due to the use of GaAs-based active area materials, the laser operating wavelength is limited to the near-infrared band (0.7μm-1.1μm), which limits the application scenarios. Summary of the invention

[0005] In view of this, an edge-emitting tunable semiconductor laser and an optical device are provided in an embodiment of the present invention.

[0006] In a first aspect, the present invention provides an edge-emitting tunable semiconductor laser, comprising: an edge-emitting component, a piezoelectric component, an external cavity mirror and a chip rear cavity mirror, wherein the piezoelectric component has a light-through hole, the edge-emitting component includes an active area, the chip rear cavity mirror is adhered to the side of the edge-emitting component and contacts one end of the active area, the other side of the edge-emitting component is adhered to the piezoelectric component, the other side of the edge-emitting component has a light-emitting cavity surface, the light-emitting cavity surface has an optical anti-reflection film, the external cavity mirror is adhered to the opposite surface of the piezoelectric component where the edge-reflecting component is installed, and the chip rear cavity mirror, the active area, the light-through hole and the external cavity mirror constitute an optical resonant cavity.

[0007] As an optional solution, the edge-emitting component includes, from top to bottom, a P-side electrode, a grating, an upper waveguide layer, the active area, a lower waveguide layer and an N-side electrode, and the active area is located between the upper waveguide layer and the lower waveguide layer.

[0008] As an optional solution, the piezoelectric component includes a first electrode and a second electrode, the first electrode covers a first surface area of ​​the piezoelectric component, and the second electrode covers a second surface area of ​​the piezoelectric component, and the first surface area and the second surface area are electrically insulated.

[0009] As an optional solution, the chip back cavity mirror has a natural cleavage surface structure or an optical coating structure.

[0010] As an optional solution, the piezoelectric component uses a piezoelectric film.

[0011] As an optional solution, the piezoelectric component and the edge-emitting component are connected by bonding.

[0012] As an optional solution, the edge emitting component adopts a distributed Bragg reflector DBR edge emitting laser or a distributed feedback DFB edge emitting laser.

[0013] As an optional solution, the edge-emitting component adopts a gallium arsenide GaAs-based laser or an indium phosphide InP-based laser.

[0014] As an optional solution, a ceramic heat sink is further included, wherein the ceramic heat sink has at least four electrode patterns, and the at least four electrode patterns are electrically connected to the P-side electrode, the N-side electrode, the first electrode, and the second electrode, respectively.

[0015] In a second aspect, the present invention provides an optical device having the above-mentioned edge-emitting tunable semiconductor laser.

[0016] An edge-emitting tunable semiconductor laser and an optical device provided in an embodiment of the present invention include an emitting component, a piezoelectric component, an external cavity mirror, and a chip rear cavity mirror, wherein the piezoelectric component has a light-through hole, the edge-emitting component includes an active region, the active region functions to generate stimulated photons through driving current excitation, the chip rear cavity mirror is attached to the side of the edge-emitting component and contacts one end of the active region, the other side of the edge-emitting component is attached to the piezoelectric component, the other side of the edge-emitting component has a light-emitting cavity surface, the light-emitting cavity surface has an optical anti-reflection film, and the optical anti-reflection film makes the cross The reflectivity of the interface is as low as possible to reduce the beam propagation loss. The external cavity mirror is attached to the opposite surface of the piezoelectric component to the edge reflection component. The chip rear cavity mirror, active area, light hole and external cavity mirror constitute an optical resonant cavity. The piezoelectric component produces a mechanical expansion effect under the drive of an external modulated voltage signal, which can change the length of the optical resonant cavity, thereby realizing the tuning of the laser working wavelength, achieving higher laser output power, and the laser working wavelength can be widened to the short-wave infrared band (1.1μm-2μm), which is conducive to expanding more application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of an edge-emitting tunable semiconductor laser is provided in an embodiment of the present invention.

[0018] Figure numerals: optical anti-reflection film 1, piezoelectric component 2, external cavity mirror 3, chip back cavity mirror 4, P-side electrode 5, active area 6, N-side electrode 7, first electrode 8, second electrode 9, grating 10, upper waveguide layer 11, lower waveguide layer 12. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0020] The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0021] Combination Figure 1 As shown, the present invention provides an edge-emitting tunable semiconductor laser, comprising: an edge-emitting component, a piezoelectric component 2, an external cavity mirror 3 and a chip rear cavity mirror 4, wherein the piezoelectric component 2 has a light-through hole, the edge-emitting component includes an active area 6, the active area 6 is used to generate stimulated photons through driving current excitation, the chip rear cavity mirror 4 is attached to the side of the edge-emitting component and contacts with one end of the active area 6, the other side of the edge-emitting component is attached to the piezoelectric component 2, the other side of the edge-emitting component has a light-emitting cavity surface, the light-emitting cavity surface has an optical anti-reflection film 1, the optical anti-reflection film 1 makes the reflectivity of the interface as low as possible to reduce the light beam propagation loss, the external cavity mirror 3 is attached to the opposite surface of the piezoelectric component 2 where the edge reflection component is installed, and the chip rear cavity mirror 4, the active area 6, the light-through hole and the external cavity mirror 3 constitute an optical resonant cavity.

[0022] It should be noted that the reflectivity of the chip back cavity mirror 4 and the external cavity mirror 3 in the embodiment of the present invention needs to be carefully designed. While ensuring the generation of the resonant cavity oscillation effect, the single longitudinal mode selection effect of the edge-emitting laser's own DBR (Distributed Feedback) or DFB (Distributed Bragg Reflction) cannot be destroyed, otherwise it will lead to the adverse consequence of multi-longitudinal mode lasing. The specific value of the reflectivity is not limited in this patent.

[0023] As an optional solution, the edge-emitting component includes, from top to bottom, a P-side electrode 5, a grating 10, an upper waveguide layer 11, the active area 6, a lower waveguide layer 12 and an N-side electrode 7, and the active area 6 is located between the upper waveguide layer 11 and the lower waveguide layer 12. It should be noted that the equipment of the edge-reflecting component can be flexibly selected according to the needs of technicians in this field, and there is no limitation on this.

[0024] In some embodiments, the edge emitting component uses a distributed Bragg reflector DBR edge emitting laser or a distributed feedback DFB edge emitting laser, which can be flexibly selected according to the needs of technical personnel in this field and is not limited to this.

[0025] In order to facilitate the understanding of the structure of the DFB edge-emitting laser, the structure and principle of the DFB edge-emitting laser are introduced in this embodiment. The laser oscillation of the DFB laser is not achieved by the F-P cavity, but by the optical coupling formed by the grating 10 distributed at equal intervals along the longitudinal direction. The period of the grating 10 is A, which is called the grating pitch. When the current is injected into the laser, the electron holes in the active region 6 recombine and radiate photons of corresponding energy. These photons will be reflected by each grating 10 on the surface of the active layer. In the distributed feedback of the DFB laser, the reflection at this time is Bragg emission. The directions of the incident light and the reflected light between the bars of the grating 10 are exactly opposite. The laser oscillation formula (1) is:

[0026]

[0027] Only those specific wavelengths of light that satisfy the laser oscillation formula (1) will be strongly reflected, thereby achieving dynamic single longitudinal mode operation. Formula (1) is also called the distributed feedback condition, λ is the wavelength, m is the coefficient usually 1, and n is a positive integer. Compared with general F-P cavity lasers, DFB lasers have the advantages of dynamic single longitudinal mode narrow linewidth output and good wavelength stability. Since the grating pitch (A) of the grating 10 in the DFB laser is very small, a micro-resonant cavity is formed, which has good selectivity for wavelength, making the threshold gain of the main mode and the side mode relatively large, thereby obtaining a linewidth that is much narrower than the F-P cavity laser and can maintain dynamic single longitudinal mode output. Since the grating 10 in the DFB laser helps to lock a given wavelength, its temperature drift is approximately / ,℃ is much better than F-P cavity laser.

[0028] In some embodiments, the edge-emitting component uses a gallium arsenide (GaAs)-based laser or an indium phosphide (InP)-based laser, which can be flexibly selected according to the needs of technicians in this field and is not limited to this.

[0029] In some embodiments, the piezoelectric component 2 includes a first electrode 8 and a second electrode 9, the first electrode 8 covers a first surface area of ​​the piezoelectric component 2, and the first surface area can be a left surface covering the piezoelectric component 2 and the left side of the upper surface as a gold wire bonding pad area, the second electrode 9 covers a second surface area of ​​the piezoelectric component 2, and the second surface area can be a right surface covering the piezoelectric component 2 and the right side of the upper surface as a gold wire bonding pad area, and the first surface area and the second surface area are electrically insulated, and ordinary technicians in this field should understand that there is no limitation on this.

[0030] In some embodiments, the chip back cavity mirror 4 has a natural cleavage surface structure or an optical coating structure, which can be flexibly selected according to the needs of technical personnel in this field, and there is no limitation on this.

[0031] In some embodiments, the piezoelectric component 2 uses a piezoelectric film, which can be flexibly selected according to the needs of technicians in this field and is not limited to this.

[0032] In some embodiments, the piezoelectric component 2 and the edge-emitting component are connected by bonding, which can be flexibly selected according to the needs of technicians in this field and is not limited to this.

[0033] In some embodiments, a ceramic heat sink is further included. The ceramic heat sink has at least four electrode patterns. The at least four electrode patterns are electrically connected to the P-side electrode 5 , the N-side electrode 7 , the first electrode 8 , and the second electrode 9 , respectively.

[0034] The working principle of the edge-emitting tunable semiconductor laser provided in the embodiment of the present invention can be realized. The piezoelectric component produces a mechanical expansion effect under the drive of an external modulation voltage signal, which can change the length of the optical resonant cavity, thereby realizing the tuning of the laser working wavelength. Since the working area of ​​the active region 6 of the edge-emitting laser is large, it can usually achieve an output optical power far higher than that of VCSEL (Vertical-Cavity Surface-Emitting Laser). The edge-emitting laser used in this application can be either a GaAs-based laser or an InP-based laser, so the working wavelength can be extended to the working wavelength of the edge-emitting laser used in principle.

[0035] An edge-emitting tunable semiconductor laser provided in an embodiment of the present invention comprises an emitting component, a piezoelectric component 2, an external cavity mirror 3 and a chip rear cavity mirror 4, wherein the piezoelectric component 2 has a light-through hole, the edge-emitting component comprises an active region 6, the active region 6 functions to generate stimulated photons through driving current excitation, the chip rear cavity mirror 4 is attached to the side of the edge-emitting component and contacts one end of the active region 6, the other side of the edge-emitting component is attached to the piezoelectric component 2, the other side of the edge-emitting component has a light-emitting cavity surface, the light-emitting cavity surface has an optical anti-reflection film 1, and the optical anti-reflection film 1 makes the cross The reflectivity of the interface is as low as possible to reduce the beam propagation loss. The external cavity mirror 3 is attached to the opposite surface of the piezoelectric component 2 where the edge reflection component is installed. The chip rear cavity mirror 4, the active area 6, the light hole and the external cavity mirror 3 constitute an optical resonant cavity. The piezoelectric component 2 produces a mechanical expansion effect under the drive of an external modulated voltage signal, which can change the length of the optical resonant cavity, thereby realizing the tuning of the laser working wavelength, achieving higher laser output power, and the laser working wavelength can be widened to the short-wave infrared band (1.1μm-2μm), which is conducive to expanding more application scenarios.

[0036] Correspondingly, an embodiment of the present invention further provides an optical device having the above-mentioned edge-emitting tunable semiconductor laser.

[0037] An optical device provided in an embodiment of the present invention can achieve higher laser output power, and the laser operating wavelength can be broadened to the short-wave infrared band (1.1μm-2μm), which is conducive to expanding more application scenarios.

[0038] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in the present disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document is not limited here.

[0039] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An edge-emitting tunable semiconductor laser, characterized in that: include: An edge-emitting component, a piezoelectric component, an external cavity mirror and a chip rear cavity mirror, wherein the piezoelectric component has a light-through hole, the edge-emitting component includes an active area, the chip rear cavity mirror is attached to the side of the edge-emitting component and contacts one end of the active area, the other side of the edge-emitting component is attached to the piezoelectric component, the other side of the edge-emitting component has a light-emitting cavity surface, the light-emitting cavity surface has an optical anti-reflection film, the external cavity mirror is attached to the opposite surface of the piezoelectric component on which the edge-emitting component is installed, and the chip rear cavity mirror, the active area, the light-through hole and the external cavity mirror constitute an optical resonant cavity.

2. The edge-emitting tunable semiconductor laser according to claim 1, characterized in that: The edge-emitting component comprises, from top to bottom, a P-surface electrode, a grating, an upper waveguide layer, the active region, a lower waveguide layer and an N-surface electrode, wherein the active region is located between the upper waveguide layer and the lower waveguide layer.

3. The edge-emitting tunable semiconductor laser according to claim 2, characterized in that: The piezoelectric component includes a first electrode and a second electrode, wherein the first electrode covers a first surface area of ​​the piezoelectric component, and the second electrode covers a second surface area of ​​the piezoelectric component, and the first surface area and the second surface area are electrically insulated from each other.

4. The edge-emitting tunable semiconductor laser according to claim 1, characterized in that: The chip rear cavity mirror has a natural cleavage surface structure or an optical coating structure.

5. The edge-emitting tunable semiconductor laser according to claim 1, characterized in that: The piezoelectric component adopts a piezoelectric film.

6. The edge-emitting tunable semiconductor laser according to claim 1 or 5, characterized in that: The piezoelectric component and the edge-emitting component are connected by bonding.

7. The edge-emitting tunable semiconductor laser according to claim 1, characterized in that: The edge emitting component adopts a distributed Bragg reflector DBR edge emitting laser or a distributed feedback DFB edge emitting laser.

8. The edge-emitting tunable semiconductor laser according to claim 1 or 7, characterized in that: The edge-emitting component adopts a gallium arsenide (GaAs)-based laser or an indium phosphide (InP)-based laser.

9. The edge-emitting tunable semiconductor laser according to claim 3, characterized in that: A ceramic heat sink is also included. The ceramic heat sink has at least four electrode patterns. The at least four electrode patterns are electrically connected to the P-side electrode, the N-side electrode, the first electrode, and the second electrode, respectively.

10. An optical device, characterized in that: An edge-emitting tunable semiconductor laser according to any one of claims 1 to 9.

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