High-precision wide-tuning hybrid integrated external cavity semiconductor laser and tuning method

Abstract

The invention discloses a high-precision wide-tuning hybrid integrated external cavity semiconductor laser and a tuning method, the high-precision wide-tuning hybrid integrated external cavity semiconductor laser comprises a semiconductor optical amplifier (1), a SiO2 expansion chip (2) and a computer (3), a silicon-based annular resonant filter (02) is integrated on the SiO2 expansion chip (2), the silicon-based annular resonant filter (02) comprises a first micro-ring resonator (001) and a second micro-ring resonator (002), and the first micro-ring resonator (001) and the second micro-ring resonator (002) are integrated on the computer (3). The first micro-ring resonator (001) and the second micro-ring resonator (002) are connected in series, and the waveguide refractive index is adjusted by utilizing a waveguide thermo-optic effect, so that'coarse 'tuning of the wavelength is realized, and a wide wavelength tuning range is obtained; and a phase shifter (04) is integrated on the SiO2 extended chip (2) and is used for finely tuning the cavity length to realize fine tuning of the wavelength. According to the invention, the micro spectrometer is integrated on the SiO2 expansion chip, the wavelength information is fed back, and the high wavelength tuning precision is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser equipment, and more specifically, relates to a high-precision, widely tuned hybrid integrated external cavity semiconductor laser and a tuning method. Background Art

[0002] Single-frequency semiconductor lasers can be used as seed sources for high-power narrow-linewidth fiber lasers. They have the characteristics of high output power, narrow linewidth, small size, light weight, long life, and good stability. They have become one of the most active and hottest research directions in the field of laser technology in the world. Intracavity feedback narrow-linewidth semiconductor lasers usually integrate Bragg gratings or special waveguide structures in the active cavity of the laser chip, such as distributed feedback (DFB) semiconductor lasers, distributed Bragg reflection (DBR) semiconductor lasers, and coupled cavity semiconductor lasers. General DFB and DBR semiconductor lasers usually use uniform or phase-shifted distributed feedback Bragg grating structures as resonant cavities. The chip size is limited to hundreds of microns, the quality factor of the resonant cavity is small, the output power is low, and the laser linewidth is generally at the level of several MHz to tens of MHz.

[0003] At present, the external cavity feedback linewidth compression technology has become the main way to obtain narrower linewidth semiconductor lasers. The external cavity semiconductor laser (ECDL) is divided into two parts, namely the active inner cavity that provides gain and the passive external cavity that provides feedback. The light emitted from the active gain medium is fed back to the gain medium after passing through the low-loss passive external medium, and the introduction of the low-loss passive external cavity increases the photon lifetime of the system, thereby narrowing the linewidth. Among them, blazed gratings, volume holographic gratings, FP etalons, whispering gallery mode (WGM) microcavities, plane mirrors, waveguide filters, interference filters and other components and their combinations can be used as external feedback elements of external cavity tunable semiconductor lasers. The above schemes are often accompanied by problems such as large volume, complex packaging, difficult optical path alignment, and mechanical tuning lag. The use of waveguide filters as external feedback elements can avoid the above problems, and the wavelength tuning range is large, but the wavelength cannot be finely tuned. The traditional solution is to use an external wavelength meter to fine-tune the wavelength according to the test results of its central wavelength, and the volume of the entire system will be larger. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a high-precision wide-tuning hybrid integrated external cavity semiconductor laser and a tuning method, which realizes "coarse" tuning of the wavelength and obtains a wide wavelength tuning range by connecting microring resonators with different free spectral ranges in series and adjusting the waveguide refractive index of the microring resonator through a thermoelectrode using the waveguide thermo-optical effect; realizes "fine" tuning of the wavelength by adjusting the cavity length through a phase shifter, and integrates a micro-spectrometer on the chip to feedback the laser wavelength information, so as to realize the iterative tuning of the tuning wavelength and obtain high wavelength tuning accuracy.

[0005] In order to achieve the above object, according to a first aspect of the present invention, a high-precision wide-tuned hybrid integrated external cavity semiconductor laser is provided, comprising a semiconductor optical amplifier, a SiO 2 An expansion chip and a computer; wherein,

[0006] The laser output by the semiconductor optical amplifier passes through the SiO 2 After the chip is expanded, the light is divided into two beams, one of which is directly output, and the wavelength information of the other beam is fed back to the computer;

[0007] The SiO 2 A silicon-based ring resonator filter is integrated on the extended chip, wherein the silicon-based ring resonator filter comprises a first micro-ring resonator and a second micro-ring resonator, wherein the first micro-ring resonator and the second micro-ring resonator having two different free spectral ranges are connected in series, and the waveguide refractive index is adjusted by using the waveguide thermo-optical effect to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range;

[0008] The SiO 2 A phase shifter is integrated on the extended chip, and the phase shifter is used to finely tune the cavity length, achieve "precise" wavelength tuning, and obtain high wavelength tuning accuracy.

[0009] Furthermore, the SiO 2 A first light spot converter is integrated on the extended chip;

[0010] The laser emitted by the broadband semiconductor optical amplifier is coupled into the silicon-based ring resonator filter through the first light spot converter.

[0011] Furthermore, the SiO 2 The second light spot converter, the optical splitter and the micro-spectrometer are integrated on the extended chip;

[0012] The laser coupled into the silicon-based ring resonant filter is divided into two paths by the optical splitter, one of which passes through the phase shifter and then outputs through the second light spot converter, and the other feeds back wavelength information to the computer through the micro-spectrometer.

[0013] Furthermore, the first light spot converter and the second light spot converter are used to directly couple the laser signal between the waveguide cross section and the optical fiber cross section.

[0014] Furthermore, the silicon-based ring resonant filter includes a first thermode and a second thermode.

[0015] Furthermore, the first hot electrode and the second hot electrode are placed on the top of the first microring resonator and the second microring resonator respectively.

[0016] Furthermore, it also includes a packaging shell, and the semiconductor optical amplifier and the SiO extension chip are integrated and packaged through the packaging shell.

[0017] Furthermore, the packaging shell adopts a standard fourteen-pin butterfly package, and the laser is output through an optical fiber pigtail.

[0018] Furthermore, the back of the broadband semiconductor optical amplifier is coated with a high reflection coating as a laser rear cavity mirror, the coupling surface of the gain chip is plated with an anti-reflection coating, and an inclined waveguide structure is used to suppress the back-reflected light on the coupling interface.

[0019] According to a second aspect of the present invention, there is provided a tuning method for a high-precision, wide-tuned hybrid integrated external cavity semiconductor laser as described above, comprising:

[0020] S100: The laser emitted by the semiconductor optical amplifier is coupled into the silicon-based ring resonant filter through the first spot converter, and then divided into two paths through the optical splitter, one of which passes through the phase shifter and then outputs through the second spot converter, and the other feeds back wavelength information to the computer through the micro-spectrometer;

[0021] S200: after comparing the wavelength information with the target wavelength, sending corresponding instructions to the first hot electrode, the second hot electrode and the phase shifter placed on the top of the first microring resonator and the second microring resonator to perform wavelength tuning iteration;

[0022] S300: adjusting the waveguide refractive index of the first microring resonator and the second microring resonator by using the first hot electrode and the second hot electrode to achieve “coarse” wavelength tuning and obtain a wide wavelength tuning range;

[0023] S400: The wavelength is precisely tuned by adjusting the cavity length through a phase shifter, and a micro-spectrometer is integrated on the chip to feedback the laser wavelength information to achieve tuning wavelength iteration and obtain high wavelength tuning accuracy.

[0024] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0025] 1. The laser of the present invention connects micro-ring resonators with different free spectral ranges in series, and uses the waveguide thermo-optical effect to adjust the waveguide refractive index of the micro-ring resonator through a thermoelectrode to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range; the cavity length is adjusted by a phase shifter to achieve "fine" wavelength tuning, and a micro-spectrometer is integrated on the chip to feedback laser wavelength information, so as to achieve iterative tuning of the wavelength and obtain high wavelength tuning accuracy.

[0026] 2. In the laser of the present invention, the first thermode and the second thermode are placed on the top of the first microring resonator and the second microring resonator respectively, and the refractive index of the microring resonator is changed by controlling the current of the thermode by utilizing the thermo-optical effect of the waveguide material, so that the transmission spectrum and the longitudinal mode of the microring resonator are shifted, thereby achieving "coarse" wavelength tuning.

[0027] 3. For the laser of the present invention, after the computer collects the wavelength information fed back by the micro-spectrometer, it compares it with the target wavelength and sends corresponding instructions to the hot electrode and the phase shifter to perform wavelength tuning iteration.

[0028] 4. The laser of the present invention has the advantages of wide wavelength tuning range, high wavelength tuning accuracy, small size and light weight.

[0029] 5. The tuning method of the present invention adjusts the waveguide refractive index of the first microring resonator and the second microring resonator through the first thermode and the second thermode to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range.

[0030] 6. The tuning method of the present invention achieves "precise" wavelength tuning by adjusting the cavity length through a phase shifter, and integrates a micro-spectrometer on the chip to feedback laser wavelength information to achieve tuning wavelength iteration and obtain high wavelength tuning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the structure of a high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to an embodiment of the present invention;

[0032] Figure 2 The figure is a flow chart of a high-precision, wide-tuned hybrid integrated external cavity semiconductor laser tuning method according to an embodiment of the present invention.

[0033] In all the drawings, the same reference numerals represent the same technical features, specifically: 1-semiconductor optical amplifier, 2-SiO 2 Extension chip, 3-computer, 4-packaging shell, 01-first light spot converter; 02-silicon-based ring resonant filter; 03-optical splitter; 04-phase shifter; 05-second light spot converter; 06-micro-spectrometer; 001-first micro-ring resonator; 002-second micro-ring resonator; 003-first hot electrode; 004-second hot electrode. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] Example 1

[0036] In view of the shortcomings of the prior art, the present invention provides a high-precision, wide-tuned hybrid integrated external cavity semiconductor laser, which uses a broadband semiconductor optical amplifier (Semiconductor Optical Amplifier, referred to as "SOA") and SiO 2 A technical solution for hybrid integration of extended chips. This solution uses two microring resonators with different free spectral ranges in series, uses the waveguide thermo-optical effect, and adjusts the waveguide refractive index of the microring resonator through a thermoelectrode to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range; adjusts the cavity length through a phase shifter to achieve "fine" wavelength tuning, and integrates a micro-spectrometer on the chip to feedback laser wavelength information to achieve tuning wavelength iteration and obtain high wavelength tuning accuracy. The present invention has the advantages of a wide wavelength tuning range, high wavelength tuning accuracy, small size, and light weight.

[0037] like Figure 1 Specifically, the laser comprises: a semiconductor optical amplifier 1, a SiO 2 The expansion chip 2, the computer 3 and the packaging shell 4. The laser output by the semiconductor optical amplifier 1 passes through the SiO 2 After the expansion chip 2 is expanded, it is divided into two laser beams, one of which is directly output, and the wavelength information of the other is fed back to the computer 3. The overall structure is integrated and packaged using the packaging shell 4.

[0038] As a further preferred embodiment, the broadband semiconductor optical amplifier 1 is both a light source and a gain medium in the laser, and has the characteristics of high performance and high stability. Its back side is designed with a high-reflection coating, and as a rear cavity mirror of the laser, it can effectively reflect the back laser and enhance the optical feedback in the resonant cavity, thereby improving the stability of the laser output. At the same time, in order to reduce the reflection loss on the coupling interface of the gain chip, an anti-reflection coating is used on its front side, which greatly reduces the reflectivity of the incident laser, thereby improving the optical power transmission efficiency.

[0039] In addition, the gain chip also uses a tilted waveguide structure design, which can effectively suppress the back-reflected light from entering the gain medium by changing the angle between the waveguide axis and the coupling interface, reducing optical noise and multi-mode interference in the cavity, and further improving the spectral purity and stability of the laser output. These optimized designs not only improve the overall performance of the optical amplifier, but also significantly improve the performance of the laser in high-precision optical communications and sensing applications, providing high-power, low-noise optical signal output.

[0040] As further preferred, the SiO 2 The expansion chip 2 integrates the first spot converter 01, the silicon-based ring resonant filter 02, the optical splitter 03, the phase shifter 04, the second spot converter 05 and the micro-spectrometer 06. The laser emitted by the broadband semiconductor optical amplifier 1 is coupled into the silicon-based ring resonant filter 02 through the first spot converter 01, and then divided into two paths through the optical splitter 03, one of which passes through the phase shifter 04 and then outputs through the second spot converter 05, and the other feeds back the wavelength information to the computer 3 through the micro-spectrometer 06.

[0041] As a further preferred embodiment, the first spot converter 01 and the second spot converter 05 play a vital role in the laser system. By achieving efficient coupling of the laser signal between the waveguide cross section and the optical fiber cross section, the coupling power is greatly improved and the system performance is optimized. The design of this spot converter is based on precise mode matching technology, which can effectively reduce the coupling loss caused by the mode size difference between the waveguide and the optical fiber. Specifically, the first spot converter 01 adjusts the laser signal emitted by the semiconductor optical amplifier from the waveguide structure to a mode size suitable for the silicon-based ring resonator, thereby ensuring that the signal can efficiently enter the ring resonator filter. Similarly, the second spot converter 05 converts the laser signal from the waveguide mode to the optical fiber mode, so that the laser output can be smoothly transmitted to the external optical fiber network. The roles of the two complement each other and jointly realize the efficient transmission of optical signals within the system. In the preferred design, the spot converter adopts a gradient refractive index waveguide structure or a tapered optical waveguide technology to achieve a smooth transition of the spot size and mode distribution, and minimize insertion loss and reflection. Its high-efficiency coupling characteristics not only improve the overall output power of optical devices, but also significantly improve the energy efficiency of laser systems, providing key technical support for high-performance optical communications, fiber optic sensing and other fields.

[0042] As a further preferred embodiment, the silicon-based ring resonator filter 02 includes a first microring resonator 001, a second microring resonator 002, a first thermode 003, and a second thermode 004. The structures and parameters of the first microring resonator 001 and the second microring resonator 002 affect the line width characteristics and tuning characteristics of the laser. The free spectrum ranges of the two are different. The vernier effect is used to select the wavelength. The transmittance reaches the maximum value at the maximum overlap of the resonance peaks where the laser longitudinal mode and the resonance spectra of the two microring resonators overlap each other, which is the laser wavelength. The first thermode 003 and the second thermode 004 are respectively placed on the top of the first microring resonator 001 and the second microring resonator 002. The thermo-optical effect of the waveguide material is used to change the refractive index of the microring resonator by controlling the current of the thermode, so that the transmission spectrum and the longitudinal mode of the microring resonator are shifted, thereby achieving "coarse" wavelength tuning.

[0043] As a further preferred embodiment, the phase shifter 04 achieves a "fine" tuning function of the wavelength by accurately adjusting the optical path length of the intracavity optical path, thereby improving the wavelength accuracy of the laser output. Specifically, the phase shifter 04 changes the phase delay of light in the waveguide by applying a controllable electrical signal and utilizing the electro-optical effect or thermo-optical effect of the material, thereby adjusting the cavity length. Compared with the traditional mechanical adjustment method, the electrically controlled phase shifter has a faster response speed and can achieve sub-nanometer tuning accuracy. In addition, by optimizing the design of the phase shifter, such as using low-loss waveguide materials and efficient electrode layouts, the insertion loss and energy consumption during the tuning process can be significantly reduced. The high-precision adjustment capability of the phase shifter 04 combined with the real-time feedback micro-spectrometer 06 ensures the stability of the output wavelength of the laser in a dynamic environment, providing key technical support for applications such as high-resolution spectral measurement, precision sensing, and quantum information processing.

[0044] As a further preferred embodiment, the micro-spectrometer 06 is used to test the spectrum output by the laser and feed back the wavelength information to the computer 3 .

[0045] As a further preferred embodiment, the computer 3 undertakes the core control task in the tuning process, and collects the real-time wavelength information fed back by the micro-spectrometer 06, and compares and analyzes it with the target wavelength, so as to achieve accurate closed-loop control. Specifically, the micro-spectrometer 06 can perform high-resolution real-time monitoring of the wavelength output by the laser, and digitizes the detected wavelength information and transmits it to the computer 3. The control algorithm built into the computer 3 will calculate and compare the feedback wavelength with the preset target wavelength to determine the deviation size and adjustment direction. According to the deviation result, the computer 3 generates corresponding adjustment instructions and sends them to the hot electrode and the phase shifter 04 respectively. The function of the hot electrode is mainly to adjust the waveguide refractive index of the microring resonator through the thermo-optical effect to complete the "coarse" tuning of the wavelength, while the phase shifter 04 achieves the "fine" tuning of the wavelength by adjusting the cavity length. The computer 3 usually adopts a hierarchical progressive strategy for the adjustment instructions of the hot electrode and the phase shifter, giving priority to completing the coarse tuning to ensure that the wavelength is close to the target value, and then performing high-precision adjustment through the phase shifter, and finally reducing the wavelength deviation to an acceptable range. The iterative characteristics of this tuning method significantly improve the tuning efficiency and accuracy. In each tuning iteration, the computer updates the control strategy in real time according to the latest feedback information, and gradually reduces the wavelength error. Through multiple rounds of iterations, the system can effectively overcome the wavelength drift caused by environmental fluctuations (such as temperature changes) and ensure the long-term stability of the output wavelength. At the same time, the efficient data processing capability of computer 3 makes the entire tuning process have the advantages of fast response and high degree of automation. In addition, the preferred control algorithm can combine historical tuning data for intelligent prediction, further optimize the tuning path, thereby reducing the number of iterations and speeding up the tuning speed. This method not only improves the availability and stability of the laser, but also provides reliable technical guarantees for complex and changeable working conditions in practical applications. Through the deep combination of computers and photonic devices, the tuning system of the present invention provides strong support for application needs in the fields of optical communication, sensor measurement and precision manufacturing.

[0046] As a further preferred embodiment, the package shell 4 adopts a standard 14-pin butterfly package to provide highly reliable mechanical protection and electrical connection for the laser. The 14-pin butterfly package is a commonly used optoelectronic device package with the characteristics of compact structure, excellent thermal management performance and convenient installation. This package can not only effectively protect the sensitive internal optoelectronic components from the influence of the external environment (such as dust, humidity and mechanical vibration), but also ensure the efficient transmission of electrical and optical signals. In the package design, the light output of the laser is led out through a high-quality optical fiber pigtail, and the optical fiber pigtail is coupled with the laser using precision alignment technology to ensure efficient transmission and low insertion loss of the output beam. In addition, the pigtail can also be configured with different connector types (such as FC / PC or LC) according to application requirements to meet the needs of fast connection in different scenarios. The standardized 14-pin design enables the package shell to have good compatibility, convenient integration with external drive circuits and thermal management systems, and also convenient installation in different optical systems. The efficient heat dissipation structure in the package further enhances the stability and reliability of the laser, providing a solid guarantee for long-term application in fields such as optical communication, precision measurement and industrial processing.

[0047] Example 2

[0048] like Figure 2 As shown, in another embodiment of the present invention, a tuning method for a high-precision wide-tuning hybrid integrated external cavity semiconductor laser is provided, comprising:

[0049] Step 1: The laser emitted by the semiconductor optical amplifier 1 is coupled into the silicon-based ring resonant filter 02 through the first spot converter 01, and then divided into two paths through the optical splitter 03, one of which passes through the phase shifter 04 and then outputs through the second spot converter 05, and the other feeds back wavelength information to the computer 3 through the micro-spectrometer 06;

[0050] Step 2: After comparing the wavelength information with the target wavelength, a corresponding instruction is sent to the first hot electrode 003, the second hot electrode 004 and the phase shifter 04 placed on the top of the first microring resonator 001 and the second microring resonator 002 to perform wavelength tuning iteration;

[0051] Step 3: adjusting the waveguide refractive index of the first microring resonator 001 and the second microring resonator 002 through the first hot electrode 003 and the second hot electrode 004 to achieve “coarse” wavelength tuning and obtain a wide wavelength tuning range;

[0052] Step 4: The cavity length is adjusted by the phase shifter 04 to achieve "precise" wavelength tuning, and the micro-spectrometer 06 is integrated on the chip to feedback the laser wavelength information to achieve tuning wavelength iteration and obtain high wavelength tuning accuracy.

[0053] Specifically, first, the semiconductor optical amplifier 1 is used as a light source, and the emitted laser enters the silicon-based ring resonator filter 02 through the first spot converter 01. The spot converter can effectively reduce the mode mismatch problem between the laser entering different waveguide materials, thereby improving the coupling efficiency and reducing the insertion loss. After entering the silicon-based ring resonator filter, the laser is subjected to a precisely designed ring structure to achieve preliminary wavelength selective filtering. This ring resonator filter can form narrow-band transmission within a specific wavelength range by adjusting the geometric parameters and material properties of the ring waveguide, thereby having a wavelength selection function. Afterwards, the optical signal is divided into two paths through the optical splitter 03, one of which outputs a laser signal after passing through the phase shifter 04 and the second spot converter 05, and the other optical signal is fed back to the control computer through the micro-spectrometer 06 for real-time wavelength information collection.

[0054] In the whole tuning process, the computer plays an important role, receiving the wavelength information fed back by the micro-spectrometer 06 in real time and comparing it with the target wavelength. According to the deviation value, the computer generates an adjustment signal through a control algorithm and sends instructions to the tuning components in the optical path, including the top thermocouples of the first microring resonator 001 and the second microring resonator 002, and the phase shifter 04. This feedback closed-loop control mechanism realizes automatic wavelength tuning to ensure that the wavelength output by the laser is highly consistent with the target wavelength. The tuning process is divided into two main stages, namely "coarse" tuning and "fine" tuning. In the "coarse" wavelength tuning stage, the first thermocouple 003 and the second thermocouple 004 apply heat to the microring resonators 001 and 002, change the refractive index of the microring waveguide through the thermo-optical effect, and then adjust the central wavelength of the microring resonance. In this process, the design of the thermocouple needs to take into account the thermal response speed, thermal efficiency and temperature control accuracy to ensure that the wavelength tuning is completed quickly and efficiently within a wide wavelength range. "Coarse" tuning is mainly used to achieve a wide range of wavelength selection and is an important basis for tuning accuracy. After completing the "coarse" tuning of the wavelength, the tuning method enters the "fine" tuning stage of the wavelength. The phase shifter 04 changes the effective cavity length of the laser's external cavity by applying an electrical signal, thereby achieving fine tuning of the optical path in the optical path. This method can achieve sub-nanometer adjustment of the wavelength and further improve the wavelength accuracy of the output laser. In addition, to achieve high-precision tuning, the micro-spectrometer 06 integrated on the chip continuously monitors the laser wavelength and feeds it back to the control computer. Through this real-time feedback mechanism, the tuning system can dynamically correct the wavelength drift caused by changes in the external environment (such as temperature fluctuations), thereby ensuring the long-term stability of the output wavelength.

[0055] Compared with traditional tuning methods, this scheme shows significant technical advantages. First, by integrating multiple functional modules on a single photonic chip, including spot converters, ring resonators, phase shifters and micro-spectrometers, a highly integrated design is achieved, which reduces the volume and cost while improving the system reliability. Secondly, this scheme combines thermal tuning and phase tuning, taking into account the tuning requirements of a wide wavelength range and high precision, making it have broad application potential in the fields of telecommunications, sensing and high-resolution spectral analysis. Furthermore, the introduction of a real-time closed-loop feedback control mechanism greatly improves the automation level of the tuning process, reduces the complexity of human intervention, and enhances the system's adaptability in dynamic environments. In practical applications, the tuning method can also be optimized according to specific needs. For example, to further improve the tuning speed, a micro-electromechanical system (MEMS)-based phase shifter can be used instead of a traditional electrically controlled phase shifter; to reduce energy consumption and thermal response time, high-efficiency thermoelectric materials and optimized thermal management designs can be introduced. In addition, by improving the resolution and detection sensitivity of the spectrometer, the accuracy of wavelength feedback can be further improved, thereby enhancing the overall tuning performance.

[0056] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-precision, widely tuned hybrid integrated external cavity semiconductor laser, characterized in that: It comprises a semiconductor optical amplifier (1), a SiO2 expansion chip (2) and a computer (3); wherein: The laser light output by the semiconductor optical amplifier (1) is divided into two beams after passing through the SiO2 expansion chip (2), one beam of light is directly output, and the wavelength information of the other beam of light is fed back to the computer (3); The SiO2 extension chip (2) integrates a silicon-based annular resonant filter (02), wherein the silicon-based annular resonant filter (02) comprises a first micro-ring resonator (001) and a second micro-ring resonator (002), wherein the first micro-ring resonator (001) and the second micro-ring resonator (002) having two different free spectral ranges are connected in series, and the waveguide refractive index is adjusted by using the waveguide thermo-optical effect to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range; The SiO2 extension chip (2) is integrated with a phase shifter (04), and the phase shifter (04) is used to finely tune the cavity length, achieve "precise" wavelength tuning, and obtain high wavelength tuning accuracy.

2. A high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to claim 1, characterized in that: The SiO2 extension chip (2) is integrated with a first light spot converter (01); The laser light emitted by the broadband semiconductor optical amplifier (1) is coupled into the silicon-based ring resonant filter (02) through the first light spot converter (01).

3. The high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to claim 1, characterized in that: The SiO2 extension chip (2) is integrated with a second light spot converter (05), an optical splitter (03) and a micro-spectrometer (06); The laser light coupled into the silicon-based ring resonant filter (02) is divided into two paths through the optical splitter (03), one of which passes through the phase shifter (04) and is output through the second light spot converter (05), and the other of which feeds back wavelength information to the computer (3) through the micro-spectrometer (06).

4. The high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to claim 3, characterized in that: The first light spot converter (01) and the second light spot converter (05) are used to directly couple the laser signal between the waveguide cross section and the optical fiber cross section.

5. A high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to any one of claims 1 to 4, characterized in that: The silicon-based ring resonant filter (02) comprises a first hot electrode (003) and a second hot electrode (004).

6. A high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to claim 5, characterized in that: The first hot electrode (003) and the second hot electrode (004) are respectively placed on the top of the first microring resonator (001) and the second microring resonator (002).

7. A high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to any one of claims 1 to 4, characterized in that: It also comprises a packaging shell (4), and the semiconductor optical amplifier (1) and the SiO2 expansion chip (2) are integrated and packaged through the packaging shell (4).

8. The high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to claim 7, characterized in that: The packaging shell (4) adopts a standard fourteen-pin butterfly package, and the laser is output through an optical fiber pigtail.

9. A high-precision, widely-tuned hybrid integrated external cavity semiconductor laser according to any one of claims 1 to 4, characterized in that: The back of the broadband semiconductor optical amplifier (1) is coated with a high reflection coating as a laser back cavity mirror, the coupling surface of the gain chip is plated with an anti-reflection coating, and an inclined waveguide structure is used to suppress the back reflection light on the coupling interface.

10. A tuning method for a high-precision, wide-tuned hybrid integrated external cavity semiconductor laser according to any one of claims 1 to 9, characterized in that: include: S100: The laser light emitted by the semiconductor optical amplifier (1) is coupled into the silicon-based ring resonant filter (02) through the first light spot converter (01), and then divided into two paths through the optical splitter (03), one of which passes through the phase shifter (04) and then outputs through the second light spot converter (05), and the other path feeds back wavelength information to the computer (3) through the micro-spectrometer (06); S200: after comparing the wavelength information with the target wavelength, sending corresponding instructions to the first hot electrode (003), the second hot electrode (004) and the phase shifter (04) placed on the top of the first microring resonator (001) and the second microring resonator (002) to perform wavelength tuning iteration; S300: adjusting the waveguide refractive index of the first microring resonator (001) and the second microring resonator (002) through the first hot electrode (003) and the second hot electrode (004) to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range; S400: The wavelength is "precisely" tuned by adjusting the cavity length through a phase shifter (04), and a micro-spectrometer (06) is integrated on the chip to feedback laser wavelength information to achieve tuning wavelength iteration and obtain high wavelength tuning accuracy.

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