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

Abstract

This invention discloses a high-precision, wide-tunable hybrid integrated external cavity semiconductor laser and its tuning method, comprising a semiconductor optical amplifier (1), a SiO2 extension chip (2), and a computer (3). A silicon-based ring resonant filter (02) is integrated on the SiO2 extension chip (2). The silicon-based ring resonant filter (02) includes a first micro-ring resonator (001) and a second micro-ring resonator (002), which are connected in series. The refractive index of the waveguide is adjusted using the waveguide thermo-optic effect to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range. A phase shifter (04) is integrated on the SiO2 extension chip (2), which is used for fine tuning of the cavity length to achieve "fine" wavelength tuning. This invention integrates a miniature spectrometer on the SiO2 extension chip to provide feedback wavelength information and achieve high wavelength tuning accuracy.

Description

Technical Field

[0001] This invention belongs to the field of laser equipment technology, and more specifically, relates to a high-precision wide-tunability hybrid integrated external cavity semiconductor laser and a tuning method. Background Technology

[0002] Single-frequency semiconductor lasers can serve as seed sources for high-power, narrow-linewidth fiber lasers, featuring high output power, narrow linewidth, small size, light weight, long lifetime, and good stability. They have become one of the most active and popular research directions in the international laser technology field. Internal cavity feedback narrow-linewidth semiconductor lasers typically integrate Bragg gratings or special waveguide structures within 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. Typical DFB and DBR semiconductor lasers usually employ uniform or phase-shifted distributed feedback Bragg grating structures as resonant cavities. Chip sizes are limited to the hundreds of micrometers, resulting in low quality factors, low output power, and laser linewidths typically ranging from a few MHz to tens of MHz.

[0003] Currently, external cavity feedback linewidth compression technology has become the main approach to obtaining narrower linewidth semiconductor lasers. An external cavity semiconductor laser (ECDL) consists of two parts: an active internal cavity providing gain and a passive external cavity providing feedback. Light emitted from the active gain medium passes through a low-loss passive external medium and is fed back to the gain medium. The introduction of the low-loss passive external cavity increases the system's photon lifetime, thereby narrowing the linewidth. Components such as blazed gratings, volume holographic gratings, FP etalons, whispering-gallery mode (WGM) microcavities, plane mirrors, waveguide filters, and interference filters, as well as combinations thereof, can all be used as external feedback elements for ECDLs. However, these solutions often suffer from problems such as large size, complex packaging, difficulty in optical path alignment, and mechanical tuning lag. Using waveguide filters as external feedback elements avoids these problems and provides a wider wavelength tuning range, but fine-tuning of the wavelength is not possible. The traditional solution is to use an external wavelength meter to fine-tune the wavelength based on the center wavelength measurement results, which further increases the overall system size. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a high-precision, wide-tunable hybrid integrated external cavity semiconductor laser and its tuning method. By connecting microring resonators with different free spectral ranges in series, and utilizing the waveguide thermo-optic effect to adjust the waveguide refractive index of the microring resonators via thermoelectrodes, "coarse" wavelength tuning is achieved, obtaining a wide wavelength tuning range. "Fine" wavelength tuning is achieved by adjusting the cavity length using a phase shifter. Furthermore, a miniature spectrometer is integrated on the chip to provide feedback on the laser wavelength information, enabling iterative tuning to achieve high wavelength tuning accuracy.

[0005] To achieve the above objectives, according to a first aspect of the present invention, a high-precision, wide-tunable hybrid integrated external cavity semiconductor laser is provided, comprising a semiconductor optical amplifier, a SiO2 extension chip, and a computer; wherein...

[0006] The laser output from the semiconductor optical amplifier is split into two beams after passing through the SiO2 expansion chip. One beam is output directly, while the wavelength information of the other beam is fed back to the computer.

[0007] The SiO2 extended chip integrates a silicon-based ring resonant filter, which includes a first micro-ring resonator and a second micro-ring resonator. The two first micro-ring resonators and second micro-ring resonators with different free spectral ranges are connected in series. The waveguide refractive index is adjusted by the waveguide thermo-optic effect to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range.

[0008] The SiO2 extended chip integrates a phase shifter, which is used to finely tune the cavity length, achieve precise wavelength tuning, and obtain high wavelength tuning accuracy.

[0009] Furthermore, a first spot converter is integrated on the SiO2 extended chip;

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

[0011] Furthermore, the SiO2 extended chip integrates a second spot converter, an optical splitter, and a miniature spectrometer;

[0012] The laser coupled into the silicon-based ring resonant filter is split into two paths by the optical splitter. One path passes through the phase shifter and is output through the second spot converter, while the other path feeds back wavelength information to the computer through the miniature spectrometer.

[0013] Furthermore, the first spot converter and the second spot converter are used to enable direct coupling of the laser signal at the waveguide cross section and the optical fiber cross section.

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

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

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

[0017] Furthermore, the package housing 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-reflectivity coating to serve as the back cavity mirror of the laser. The coupling surface of the gain chip is coated with an anti-reflection coating and a tilted waveguide structure is used to suppress back-reflected light at the coupling interface.

[0019] According to a second aspect of the present invention, a tuning method for a high-precision wide-tunability hybrid integrated external cavity semiconductor laser as described above is provided, 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 split into two paths by the optical splitter. One path passes through the phase shifter and is output through the second spot converter, while the other path feeds back wavelength information to the computer through the miniature spectrometer.

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

[0022] S300: By adjusting the waveguide refractive index of the first and second micro-ring resonators through the first and second thermoelectrodes, "coarse" wavelength tuning can be achieved to obtain a wide wavelength tuning range.

[0023] S400: It achieves precise wavelength tuning by adjusting the cavity length through a phase shifter, and integrates a miniature spectrometer on the chip to feed back laser wavelength information to achieve iterative tuning of the wavelength and obtain high wavelength tuning accuracy.

[0024] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0025] 1. The laser of the present invention uses microring resonators with different free spectral ranges connected in series. By utilizing the waveguide thermo-optic effect, the refractive index of the microring resonators is adjusted through thermoelectrodes 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. A micro spectrometer is integrated on the chip to feed back laser wavelength information, so as to achieve high wavelength tuning accuracy through iterative tuning.

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

[0027] 3. In 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 thermoelectrode 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 thermoelectrode and the second thermoelectrode 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 feed back laser wavelength information to achieve tuning wavelength iteration and obtain high wavelength tuning accuracy. Attached Figure Description

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

[0032] Figure 2 This is a schematic diagram of the high-precision wide-tuning hybrid integrated external cavity semiconductor laser tuning method according to an embodiment of the present invention.

[0033] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-semiconductor optical amplifier, 2-SiO2 extended chip, 3-computer, 4-package housing, 01-first spot converter; 02-silicon-based ring resonant filter; 03-optical splitter; 04-phase shifter; 05-second spot converter; 06-miniature spectrometer; 001-first micro-ring resonator; 002-second micro-ring resonator; 003-first thermoelectrode; 004-second thermoelectrode. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0035] Example 1

[0036] To address the shortcomings of existing technologies, this invention provides a high-precision, wide-tunable hybrid integrated external cavity semiconductor laser, employing a hybrid integration of a broadband semiconductor optical amplifier (SOA) and a SiO2 extended chip. This solution uses two microring resonators with different free spectral ranges connected in series. Utilizing the waveguide thermo-optic effect, the refractive index of the microring resonators is adjusted via thermoelectrodes to achieve coarse wavelength tuning, obtaining a wide wavelength tuning range. Fine wavelength tuning is achieved by adjusting the cavity length using a phase shifter. A miniature spectrometer is integrated on the chip to provide feedback on the laser wavelength information, enabling iterative tuning and achieving high wavelength tuning accuracy. This invention offers advantages such as a wide wavelength tuning range, high wavelength tuning accuracy, small size, and light weight.

[0037] like Figure 1 As shown, specifically, the laser includes: a semiconductor optical amplifier 1, a SiO2 extension chip 2, a computer 3, and a packaging shell 4. The laser output from the semiconductor optical amplifier 1 is split into two laser beams after passing through the SiO2 extension chip 2. One beam is output directly, while the wavelength information of the other beam 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 serves as both a light source and a gain medium in the laser, exhibiting high performance and high stability. Its back side features a high-reflectivity coating, acting as the rear cavity mirror of the laser to effectively reflect back-facing laser light, enhancing optical feedback within the resonant cavity and thus improving the stability of the laser output. Simultaneously, to reduce reflection losses at the gain chip coupling interface, its front side employs an anti-reflection coating, significantly reducing the reflectivity of the incident laser and thereby improving optical power transmission efficiency.

[0039] Furthermore, the gain chip employs a tilted waveguide structure design. This structure, by altering the angle between the waveguide axis and the coupling interface, effectively suppresses back-reflected light from entering the gain medium, reducing optical noise and intracavity multimode interference, and further enhancing 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 enhance the laser's performance in high-precision optical communication and sensing applications, providing high-power, low-noise optical signal output.

[0040] As a further preferred embodiment, the SiO2 extended chip 2 integrates components such as a first spot converter 01, a silicon-based ring resonant filter 02, an optical splitter 03, a phase shifter 04, a second spot converter 05, and a miniature 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 split into two paths by the optical splitter 03. One path passes through the phase shifter 04 and is output through the second spot converter 05, while the other path feeds back wavelength information to the computer 3 through the miniature spectrometer 06.

[0041] As a further preferred embodiment, the first spot converter 01 and the second spot converter 05 play a crucial role in the laser system. By enabling efficient coupling of the laser signal between the waveguide cross-section and the fiber cross-section, they significantly improve coupling power and optimize system performance. This spot converter design is based on precise mode-matching technology, which effectively reduces coupling loss caused by mode size differences between the waveguide and the fiber. Specifically, the first spot converter 01 adjusts the laser signal emitted from 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 resonant filter. Similarly, the second spot converter 05 converts the laser signal from the waveguide mode to the fiber mode, enabling the laser output to be smoothly transmitted to the external fiber optic network. Their functions complement each other, jointly achieving efficient transmission of the optical signal within the system. In a preferred design, the spot converter employs a graded-index waveguide structure or tapered waveguide technology to achieve a smooth transition in spot size and mode distribution, minimizing insertion loss and reflection. Its high-efficiency coupling characteristics not only improve the overall output power of optical devices, but also significantly enhance the energy efficiency ratio of laser systems, providing key technical support for high-performance optical communication, fiber optic sensing and other fields.

[0042] As a further preferred embodiment, the silicon-based ring resonant filter 02 comprises a first micro-ring resonator 001, a second micro-ring resonator 002, a first thermoelectric electrode 003, and a second thermoelectric electrode 004. The structure and parameters of the first micro-ring resonator 001 and the second micro-ring resonator 002 affect the linewidth and tuning characteristics of the laser. Since their free spectral ranges differ, wavelength selection is achieved using their vernier effect. The transmittance reaches its maximum value at the point of maximum overlap between the laser longitudinal mode and the resonance peaks of the two micro-ring resonators; this point represents the laser wavelength. The first thermoelectric electrode 003 and the second thermoelectric electrode 004 are respectively placed on top of the first micro-ring resonator 001 and the second micro-ring resonator 002. Utilizing the thermo-optical effect of the waveguide material, the refractive index of the micro-ring resonator is changed by controlling the current of the thermoelectric electrodes, causing a shift in the transmission spectrum and longitudinal mode of the micro-ring resonator, thereby achieving "coarse" wavelength tuning.

[0043] As a further preferred embodiment, the phase shifter 04 achieves precise wavelength tuning by accurately adjusting the optical path length within the cavity, thereby improving the wavelength accuracy of the laser output. Specifically, the phase shifter 04 adjusts the cavity length by applying a controllable electrical signal and utilizing the electro-optic or thermo-optic effects of the material to change the phase delay of light in the waveguide. Compared to traditional mechanical adjustment methods, the electrically controlled phase shifter has a faster response speed and can achieve sub-nanometer level tuning accuracy. Furthermore, by optimizing the phase shifter design, such as using low-loss waveguide materials and efficient electrode layout, insertion loss and energy consumption during tuning 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 laser's output wavelength in dynamic environments, 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 miniature spectrometer 06 is used to test the spectrum output by the laser and to feed back wavelength information to the computer 3.

[0045] As a further preferred embodiment, the computer 3 undertakes the core control task during the tuning process. By collecting real-time wavelength information fed back by the micro spectrometer 06 and comparing it with the target wavelength, it achieves precise closed-loop control. Specifically, the micro spectrometer 06 can perform high-resolution real-time monitoring of the wavelength output by the laser and transmit the detected wavelength information to the computer 3 after digitization. The control algorithm built into the computer 3 calculates and compares the feedback wavelength with the preset target wavelength to determine the magnitude of the deviation and the adjustment direction. Based on the deviation result, the computer 3 generates corresponding adjustment commands and sends them to the thermoelectrode and the phase shifter 04, respectively. The thermoelectrode mainly adjusts the waveguide refractive index of the micro-ring resonator through the thermo-optic 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 typically adopts a step-by-step strategy for the adjustment commands of the thermoelectrode and the phase shifter, first 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 to finally reduce 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 based on the latest feedback information, gradually reducing the wavelength error. Through multiple iterations, the system can effectively overcome wavelength drift caused by environmental fluctuations (such as temperature changes), ensuring the long-term stability of the output wavelength. Simultaneously, the efficient data processing capabilities of the computer enable the entire tuning process to have the advantages of rapid response and high automation. Furthermore, the optimized control algorithm can intelligently predict based on historical tuning data, further optimizing the tuning path, thereby reducing the number of iterations and accelerating the tuning speed. This method not only improves the availability and stability of the laser but also provides reliable technical support for complex and variable operating conditions in practical applications. Through the deep integration of computers and photonic devices, the tuning system of this invention provides strong support for application needs in fields such as optical communication, sensing and measurement, and precision manufacturing.

[0046] As a further preferred embodiment, the package housing 4 adopts a standard 14-pin butterfly package, providing highly reliable mechanical protection and electrical connection for the laser. The 14-pin butterfly package is a commonly used packaging form for optoelectronic devices, characterized by its compact structure, excellent thermal management performance, and convenient installation. This packaging form not only effectively protects the internal sensitive optoelectronic components from the influence of the external environment (such as dust, humidity, and mechanical vibration), but also ensures efficient transmission of electrical and optical signals. In the package design, the laser's optical output is led out through a high-quality fiber optic pigtail, which is coupled to the laser using precision alignment technology to ensure efficient transmission of the output beam and low insertion loss. Furthermore, the pigtail can be configured with different connector types (such as FC / PC or LC) according to application requirements to meet the rapid connection needs of different scenarios. The standardized 14-pin design gives the package housing good compatibility, facilitating integration with external drive circuits and thermal management systems, and also making it easy to install in different optical systems. The efficient heat dissipation structure within the package further enhances the stability and reliability of the laser, providing a solid guarantee for long-term applications 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-tunable 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 split into two paths by the optical splitter 03. One path passes through the phase shifter 04 and is output through the second spot converter 05, while the other path feeds back wavelength information to the computer 3 through the miniature spectrometer 06.

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

[0051] Step 3: Adjust the waveguide refractive index of the first microring resonator 001 and the second microring resonator 002 by using the first thermoelectric electrode 003 and the second thermoelectric electrode 004 to achieve "coarse" wavelength tuning and obtain a wide wavelength tuning range.

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

[0053] Specifically, firstly, the semiconductor optical amplifier 1, acting as a light source, emits laser light that enters the silicon-based ring resonant filter 02 via a first spot converter 01. The spot converter effectively reduces mode mismatch issues between different waveguide materials, thereby improving coupling efficiency and reducing insertion loss. After entering the silicon-based ring resonant filter, the laser undergoes preliminary wavelength-selective filtering through a precisely designed ring structure. This ring resonant filter, by adjusting the geometric parameters and material properties of the ring waveguide, can form narrowband transmission within a specific wavelength range, thus possessing wavelength selectivity. Next, the optical signal is split into two paths by an optical splitter 03. One path passes through a phase shifter 04 and a second spot converter 05 to output the laser signal, while the other path is fed back to the control computer via a miniature spectrometer 06 for real-time wavelength information acquisition.

[0054] Throughout the tuning process, the computer plays a crucial role, receiving wavelength information from the miniature spectrometer 06 in real time and comparing it with the target wavelength. Based on 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 thermoelectrodes of the first microring resonator 001 and the second microring resonator 002, as well as the phase shifter 04. This feedback closed-loop control mechanism achieves automated wavelength tuning, ensuring that the laser output wavelength is highly consistent with the target wavelength. The tuning process is divided into two main stages: "coarse" tuning and "fine" tuning. In the "coarse" wavelength tuning stage, the first thermoelectrode 003 and the second thermoelectrode 004 apply heat to the microring resonators 001 and 002, changing the refractive index of the microring waveguide through the thermo-optic effect, thereby adjusting the center wavelength of the microring resonance. In this process, the design of the thermoelectrodes needs to consider thermal response speed, thermal efficiency, and temperature control accuracy to ensure rapid and efficient wavelength tuning over a wide wavelength range. "Coarse" tuning is mainly used to achieve a wide range of wavelength selection and is an important foundation for tuning accuracy. After completing the coarse wavelength tuning, the tuning method enters the fine wavelength tuning stage. 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. This method enables sub-nanometer-level wavelength adjustment, further improving the wavelength accuracy of the output laser. Furthermore, to achieve high-precision tuning, a miniature 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 wavelength drift caused by changes in the external environment (such as temperature fluctuations), thus ensuring the long-term stability of the output wavelength.

[0055] Compared to traditional tuning methods, this approach exhibits significant technical advantages. First, by integrating multiple functional modules—including a spot converter, ring resonator, phase shifter, and miniature spectrometer—on a single photonic chip, a highly integrated design is achieved, reducing size and cost while improving system reliability. Second, this approach combines thermal tuning and phase tuning, balancing the requirements of a wide wavelength range and high precision, making it widely applicable in telecommunications, sensing, and high-resolution spectral analysis. Furthermore, the introduction of a real-time closed-loop feedback control mechanism significantly 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 be optimized according to specific needs. For example, to further improve tuning speed, a microelectromechanical system (MEMS)-based phase shifter can be used instead of a traditional electrically controlled phase shifter; to reduce energy consumption and thermal response time, highly efficient thermoelectric materials and optimized thermal management design 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 overall tuning performance.

[0056] Those skilled in the art will readily understand that the above description is merely 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 within the scope of protection of the present invention.

Claims

1. A high-precision wide-tuning 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 output by the semiconductor optical amplifier (1) is divided into two beams after passing through the SiO2 expansion chip (2), one of which is directly output, and the wavelength information of the other is fed back to the computer (3); The SiO2 expansion chip (2) is integrated with a silicon-based ring resonant filter (02), the silicon-based ring resonant filter (02) comprises a first micro-ring resonator (001) and a second micro-ring resonator (002), the two first micro-ring resonator (001) and second micro-ring resonator (002) with different free spectral ranges are connected in series, the waveguide refractive index of which is adjusted by using the waveguide thermo-optic effect, realizing wavelength "coarse" tuning and obtaining a wide wavelength tuning range; the SiO2 expansion chip (2) is integrated with a second spot converter (05), an optical splitter (03) and a micro-spectrometer (06); The SiO2 expansion chip (2) is integrated with a phase shifter (04), which is used for fine tuning of the cavity length, realizing wavelength "fine" tuning and obtaining high wavelength tuning accuracy; The silicon-based ring resonant filter (02) comprises a first heating electrode (003) and a second heating electrode (004); The computer (3) compares and analyzes the real-time wavelength information fed back by the micro-spectrometer (06) with the target wavelength, so as to realize accurate closed-loop control. The micro-spectrometer (06) can monitor the wavelength output by the laser in high resolution in real time, and transmit the detected wavelength information to the computer (3) after digitization. The control algorithm built in the computer (3) compares and calculates the feedback wavelength with the preset target wavelength, determines the deviation size and adjustment direction, and generates corresponding adjustment instructions according to the deviation result, and sends them to the heating electrode and the phase shifter (04) respectively. The main function of the heating electrode is to adjust the waveguide refractive index of the micro-ring resonator through the thermo-optic effect, so as to complete the "coarse" tuning of the wavelength, while the phase shifter (04) realizes the "fine" tuning of the wavelength by adjusting the cavity length.

2. The high-precision wide-tuning hybrid integrated external cavity semiconductor laser according to claim 1, characterized in that, The SiO2 expansion chip (2) is integrated with a first spot converter (01); 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).

3. The high-precision wide-tuning hybrid integrated external cavity semiconductor laser of claim 2, wherein, The laser coupled into the silicon-based ring resonant filter (02) is divided into two paths by the optical splitter (03), one of which is output through the second spot converter (05) after passing through the phase shifter (04), and the other of which feeds back the wavelength information to the computer (3) through the micro-spectrometer (06).

4. The high-precision wide-tuning hybrid integrated external cavity semiconductor laser of claim 3, wherein, The first spot converter (01) and the second spot converter (05) are used to directly couple the laser signal between the waveguide cross section and the fiber cross section.

5. The high-precision wide-tuning hybrid integrated external cavity semiconductor laser of claim 1, wherein, The first heating electrode (003) and the second heating electrode (004) are respectively arranged on the top of the first micro-ring resonator (001) and the second micro-ring resonator (002).

6. The high-precision wide-tuning hybrid integrated external cavity semiconductor laser of any one of claims 1-5, wherein, Also include the package shell (4), the semiconductor optical amplifier (1) and SiO2 extension chip (2) are integrated by package shell (4) package.

7. The high-precision wide-tuning hybrid integrated external cavity semiconductor laser according to claim 6, characterized in that, The package shell (4) adopts standard fourteen pin butterfly package, and the laser is output through the fiber tail fiber.

8. The high-precision wide-tuning hybrid integrated external cavity semiconductor laser of any one of claims 1-4, wherein, The back of the semiconductor optical amplifier (1) is high reflection coating, as the laser rear cavity mirror, the coupling surface of gain chip is coated with anti-reflection coating, and the inclined waveguide structure is adopted to suppress the backward reflection light on the coupling interface.

9. A tuning method of the high-precision wide-tuning hybrid integrated external cavity semiconductor laser according to any one of claims 1-8, characterized in that, It comprises: S100: 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 passes through the optical splitter (03) to be divided into two ways, one of which is output after passing through the phase shifter (04) through the second spot converter (05), and the other is fed back to the computer (3) through the micro spectrometer (06) wavelength information; S200: after comparing the wavelength information with the target wavelength, corresponding instructions are sent to the first thermoelectric electrode (003) and the second thermoelectric electrode (004) placed on the top of the first micro ring resonator (001) and the second micro ring resonator (002) to tune the wavelength iteration; S300: the waveguide refractive index of the first micro ring resonator (001) and the second micro ring resonator (002) is adjusted by the first thermoelectric electrode (003) and the second thermoelectric electrode (004), the wavelength "coarse" tuning is realized, and a wide wavelength tuning range is obtained; S400: the wavelength "fine" tuning is realized by adjusting the cavity length through the phase shifter (04), and the micro spectrometer (06) is integrated on the chip to feed back the laser wavelength information to realize the tuning wavelength iteration and obtain high wavelength tuning accuracy.

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