38 results about "Laser linewidth" patented technology

The invention relates to the technical field of optoelectronic devices, in particular to a laser based on two different gratings and a metal grating with a phase interval of lambda / 2, which comprises a gain chip, a gain chip optical waveguide, an optical waveguide substrate, an optical waveguide, an annular resonant optical waveguide and a metal BRAGG reflecting grating. A unique outer cavity structure is adopted, a traditional interlayer semiconductor grating is abandoned, a top metal grating is adopted, a traditional DFB sandwich type secondary epitaxy manufacturing process is greatly simplified and avoided, the production cost is reduced, particularly, the metal grating is divided into two parts with similar but different grating constants, and the phase positions of the two gratings are pulled by lambda / 2, so that the performance of the DFB is improved. According to the design, the side mode rejection ratio (SMSR) of laser beams can be effectively improved, the laser line width is compressed, a guarantee is provided for stable work of the laser in a high-performance application scene, and the grating reflection efficiency is effectively improved by combining a'mouth-to-mouth 'coupling butt joint mode of the gain chip and the optical waveguide substrate.

The invention relates to the technical field of sensing, and discloses a demodulator chip with a phase noise compensation function and an optical fiber sound wave sensing system, and the demodulator chip comprises an optical port module, a first polarization filter, a beam splitter module, a modulator, a coherent receiving module and a phase noise extraction module. The optical port module is used for acquiring an incident laser signal, outputting probe light, acquiring scattered light and coupling with the delay optical fiber; the first polarization filter is connected with the optical port module; the beam splitter module is connected with the first polarization filter; the beam splitter module is connected with the optical port module through the modulator; the coherent receiving module is connected with the beam splitter module; the coherent receiving module is connected with the optical port module; the beam splitter module is connected with the phase noise extraction module, and the phase noise extraction module is connected to the delay optical fiber; the phase noise extraction module is used for extracting phase noise through a delay self-coherence mode; the requirement for the laser line width can be lowered, and the sensing performance under the same laser line width level is improved.

This invention provides a self-heterodyne detection system capable of stably and over long periods of time measuring broadband laser linewidths. [Solution] The present invention discloses a self-heterodyne detection system. The system may include a frequency comb light source that generates light, a photodetector that detects the light, an electrical spectrum analyzer connected to the photodetector that analyzes the frequency and wavelength of the light using the detection signal of the photodetector, an interferometer including an input coupler provided between the frequency comb light source and the photodetector to receive the light, a branch waveguide branched by the input coupler, and an output coupler connected to the branch waveguide, and a programmable filter provided in the branch waveguide to select the peak wavelength of the light.

Disclosed is an optical feedback cavity ring-down spectroscopy system without phase control. The system comprises: a light source module, used for generating a laser of a predetermined wavelength; an optical feedback module, used for feeding back a part of the laser generated by the light source module into the light source module, and generating strong feedback or moderate feedback, so as to narrow the line width of the laser; an optical cavity module, used for increasing the effective action distance between the laser and a target detection substance, and exciting an optical cavity ring-down signal by means of achieving resonance between the laser and an optical cavity; a trigger light-cutting module, used to instantaneously cut off incident light of the optical cavity module to facilitate detection; a detection module, used to detect a transmitted optical signal outputted by the optical cavity module, convert the transmitted optical signal into a voltage signal, to be used as an optical cavity ring-down signal; and a data acquisition module, used to acquire the optical cavity ring-down signal outputted by the detection module, and perform exponential fitting on the optical cavity ring-down signal to obtain a ring-down time.

The application relates to a kind of multi-channel short delay optical fiber laser linewidth measurement methods, the laser to be measured is divided into multiple channels by coupler after passing through optical isolator, wherein the first group of optical signals are frequency-shifted by acousto-optic modulator, the remaining optical signals are coupled with the first group of frequency-shifted optical signals after passing through different lengths of short delay optical fiber, converted into optical signals after input to photodetector, finally output to oscilloscope or spectrum analyzer to extract the power difference of power spectrum first-order envelope peak and second-order envelope peak, and finally the linewidth parameter of the laser to be measured is obtained by correlation processing. The application can effectively reduce the length of delay optical fiber, reduce the sensitivity of the system to environmental vibration interference by 100 times, and the multi-channel information collection of different lengths of delay optical fiber can obtain the average level of the laser linewidth output in a time period and under a working state at one time, which is beneficial to eliminate the accidental error influence in linewidth measurement.

The utility model discloses a laser line width measuring device based on a short optical fiber, relates to the technical field of delayed self-heterodyne measurement, and aims to solve the problem that a laser line width measuring result is inaccurate due to the existence of 1 / f frequency noise in the conventional delayed self-heterodyne technology. In the device, laser to be measured is divided into two laser beams through the first coupler, one laser beam enters the acousto-optic modulator, the other laser beam enters the gear-adjustable short optical fiber delay line device, and the laser emitted from the acousto-optic modulator and the laser emitted from the gear-adjustable short optical fiber delay line device are combined through the second coupler and then are transmitted to the second coupler. And the high-speed photoelectric detector is used for detecting, and detection data is sent to the electric spectrum analyzer. The shift-adjustable short optical fiber delay line device has a plurality of shifts, different shifts correspond to delay optical fibers with different lengths, 1 / f frequency noise can be effectively avoided, the laser line width measurement precision is improved, the laser line width measurement range is expanded, and the shift-adjustable short optical fiber delay line device is suitable for measurement of lasers with various line widths.

The application discloses a narrow-linewidth laser external cavity coupling system and method based on linewidth test feedback, adopts a self-feedback mechanism to perform external cavity coupling, wherein through optical power real-time feedback, the laser can be ensured to be in the best working state when measuring the linewidth, so that the accuracy of the linewidth measurement can be improved, and reliable data can be provided for subsequent external cavity position adjustment; after the linewidth measurement is completed, the external cavity clamp displacement table can be controlled to adjust the position of the external cavity of the narrow-linewidth laser according to the linewidth, until the linewidth of the laser output by the external cavity reaches a preset target, and the best coupling position of the external cavity can be determined; thus, the application comprehensively considers the optical power and the laser linewidth to perform external cavity coupling, can ensure that the actual performance meets the design index, ensures the parameter consistency, and the whole process is fully automated, without the intervention of personnel, effectively avoiding the subjective influence of the operator, so that the process stability and the production efficiency are improved.

This invention discloses a method and apparatus for detecting the linewidth of a narrow-linewidth laser. The method includes acquiring data information pre-collected using a data acquisition card; preprocessing the data information using a cumulative averaging algorithm; performing a fast Fourier transform on the preprocessed time-domain data information; processing the data using a moving average algorithm; fitting the moving averaged data using an L-M algorithm; and detecting the linewidth of the fitted data using a time-delayed self-heterodyne method to calculate the laser linewidth data. This invention uses a time-delayed fiber beat frequency method to measure the linewidth of a narrow-linewidth laser, which greatly enhances the accuracy of laser linewidth measurement while reducing the number of components used. This method uses a data acquisition card for data acquisition, fast Fourier transform for analysis and processing, and moving average and L-M algorithms for data processing, reducing costs while accurately detecting narrower laser linewidths.

Provided in the embodiments of the present application are a copper-grid-line solar cell and a preparation method therefor. When the copper-grid-line solar cell is prepared, a first exposure and a second exposure are sequentially performed on a photosensitive region of a negative photosensitive ink layer (700), wherein a laser line width and an energy density during the first exposure are both different from a laser line width and an energy density during the second exposure; development processing is then performed, so as to remove the part in a shading region and form gridline grooves; and electroplating processing is then performed, so as to form copper gridlines (800) in the gridline grooves.

The application provides a laser linewidth adaptive narrowing optical resonant cavity design method and system, temperature distribution data of an optical resonant cavity surface is collected, the temperature distribution data contains coordinate information and temperature values of each temperature measurement point; based on the temperature distribution data, a deformation gradient of the optical resonant cavity is calculated; the deformation gradient is linearly converted to generate an initial compensation signal, and based on a preset deformation threshold, an electrical compensation signal is obtained; according to the electrical compensation signal, an adjusted cavity mirror spacing is obtained; the deformation gradient is compensated by using the adjusted cavity mirror spacing to offset the instantaneous deformation, and the cavity structure of the optical resonant cavity is stably adjusted by using a preset thermal expansion coefficient, so as to cooperatively realize adaptive narrowing of the laser linewidth; the technical scheme provided by the application realizes dynamic adjustment of the cavity mirror spacing to compensate for the instantaneous thermal deformation, thereby adaptively narrowing the laser linewidth, and the frequency stability and output precision of the laser are improved.

The application discloses a chipped wavelength standard device and a preparation method thereof, and belongs to the field of wavelength standards. The device comprises a frequency discrimination module, a pumping module, a locking module and a substrate. The frequency discrimination module comprises a MEMS atomic gas chamber, a micro-ring resonant cavity and a photodetector; the pumping module mainly comprises a laser and a control circuit thereof; the locking module comprises a phase-locked amplifier, a reference signal source and a PID circuit. The substrate comprises a copper or ceramic heat sink and a TEC temperature controller. The application combines the micro-ring resonant cavity and the MEMS atomic gas chamber, directly pumps the micro-ring resonant cavity integrated optical path by the laser, locks the laser wavelength on the micro-ring resonant cavity resonance peak based on the micro-cavity self-injection locking method, reduces the laser noise and realizes the laser linewidth compression. The micro-cavity evanescent field excites the atomic transition in the atomic gas chamber, and the frequency is discriminated by detecting the fluorescence. The laser frequency is locked by controlling the laser current and the micro-cavity temperature through the frequency discrimination signal, and the chip-level wavelength metrology and value traceability are realized.

This invention discloses a laser linewidth measurement device and method based on switchable channel delay self-heterodyne interferometry, belonging to the field of laser linewidth measurement technology. The laser to be measured is incident on a first fiber coupler via an isolator and splits into two paths: one path enters a computer-controlled first and second optical switches via a three-port fiber circulator, switching between different lengths of delay fiber via the first and second optical switches, rotating the polarization state by 90° via a Faraday rotating mirror before returning along the original path, and then restoring the original polarization state via a polarization controller; the other path undergoes frequency shifting via an acousto-optic frequency shifter. The two paths are combined via a second fiber coupler to generate a beat frequency optical signal, which is then acquired by a photodetector for photoelectric conversion and a spectrum analysis module. The computer fits the beat frequency power spectrum corresponding to different delay lengths to obtain the laser linewidth to be measured. This invention has strong anti-interference capabilities and can simultaneously acquire Lorentz linewidth, Gaussian linewidth, and composite linewidth, with a wide linewidth measurement range.

The application provides a mid-infrared laser linewidth measurement device and method based on a hollow-core anti-resonant fiber, and belongs to the technical field of precise laser parameter measurement. The device comprises a mid-infrared single-frequency laser, a first collimating lens, a beam splitter, an acousto-optic modulator, an aperture, a first mirror, a converging lens, a hollow-core anti-resonant fiber, a second collimating lens, a second mirror, a beam combiner, a photodetector and a spectrum analyzer. The method is as follows: after the laser is split, one path is frequency-shifted, and the other path is introduced into a time delay through the fiber; beat frequency signals are generated by interference of the two paths of light; and the linewidth is obtained through photoelectric conversion and spectrum analysis. The application takes a low-loss hollow-core anti-resonant fiber as a core delay element, solves the problem of difficulty in realizing long optical path delay in the mid-infrared waveband, has the advantages of compact structure, convenient adjustment, wide applicable waveband and high measurement precision, and is suitable for precise linewidth measurement of a 2-5 mu m single-frequency laser.

An integrated optical linewidth reduction system based on optical feedback and a low-speed electronic control loop to control the optical feedback. Light is tapped and reflected back to the laser with an amplitude, phase or both amplitude and phase adjustment such that the linewidth of the laser is lower than the free-running laser linewidth. The amplitude of the feedback signal may be controlled using an optical attenuator. The phase of the feedback signal may be controlled using a phase shifter. The amplitude of the optical feedback may be monitored by means of a filter and a photodetector, or just a photodetector. The amplitude and / or phase of the optical feedback is monitored by means of a frequency / phase noise discriminator. The phase shifter can be an endless phase shifter.

The invention discloses a narrow linewidth laser external cavity coupling system and a narrow linewidth laser external cavity coupling method based on linewidth test feedback, external cavity coupling is carried out by adopting a self-feedback mechanism, and through real-time feedback of optical power, the laser can be ensured to be in an optimal working state when the linewidth is measured, so that the accuracy of linewidth measurement can be improved, and the measurement accuracy is improved. Reliable data can be provided for subsequent adjustment of the position of the external cavity; after the line width measurement is completed, the outer cavity clamp displacement table can be controlled to adjust the position of the outer cavity of the narrow-line-width laser according to the line width until the line width of the laser output by the outer cavity reaches a preset target, and the optimal coupling position of the outer cavity can be determined; therefore, the optical power and the laser line width are integrated to perform external cavity coupling, the actual performance can be ensured to conform to the design index, the parameter consistency is ensured, the whole process is automatic and does not need personnel intervention, the subjective influence of operators is effectively avoided, and the process stability and the production efficiency are improved.

According to the laser frequency locking device and method, the self-injection locking technology is introduced into the tunable laser, laser frequency locking is achieved in a wide tuning range in an all-optical feedback mode, a feedback control circuit does not need to be externally connected, miniaturization packaging can be achieved, the laser line width can be narrowed, and low-frequency noise can be restrained; and the channel switching speed can also be improved. Comprising a laser for outputting laser with tunable wavelength; the wavelength locker locks laser wavelengths output by the laser to a plurality of specified wavelengths and outputs the laser wavelengths, the wavelength locker comprises a filtering unit and an optical feedback unit, and the laser output by the laser is fed back to the laser through the optical feedback unit after being filtered by the filtering unit. The filtering unit is used for realizing self-injection locking of laser, a transmission spectrum or a reflection spectrum of the filtering unit is provided with a plurality of harmonic peaks respectively corresponding to the plurality of specified wavelengths, and the wavelength tuning range of the laser covers the plurality of specified wavelengths.

The application relates to the technical field of sensing, and discloses a demodulator chip with a phase noise compensation function and an optical fiber acoustic wave sensing system, which comprises an optical port module, a first polarization filter, a beam splitter module, a modulator, a coherent receiving module and a phase noise extraction module; the optical port module is used for acquiring an incident laser signal, outputting detection light, acquiring scattered light and coupling with a delay optical fiber; the first polarization filter is connected with the optical port module; the beam splitter module is connected with the first polarization filter; the beam splitter module is connected with the optical port module through the modulator; the coherent receiving module is connected with the beam splitter module; the coherent receiving module is connected with the optical port module; the beam splitter module is connected with the phase noise extraction module, and the phase noise extraction module is connected to the delay optical fiber; the phase noise extraction module is used for extracting phase noise through a delay self-coherence mode; the laser linewidth demand can be reduced, and the sensing performance under the same laser linewidth level can be improved.

This invention belongs to the field of laser equipment technology, specifically disclosing an ultra-narrow linewidth vertical external cavity surface-emitting laser (VECS), including a laser resonator unit and an intracavity control unit. The laser resonator unit is used to generate laser oscillation, and the intracavity control unit is used to perform polarization control, mode control, wavelength tuning, and linewidth narrowing of the fundamental frequency light. The laser resonator unit includes a pump light emission system, a gain chip, a folded output mirror, and a back-end mirror. The intracavity control unit includes a beam splitter, a polarization element, a mode control element, a wavelength tuning element, a linewidth narrowing element, and an output coupling mirror. The second harmonic self-suppression of the mode control element is used to control the laser mode in the resonant cavity to achieve single-frequency lasing, which simplifies the design and adjustment difficulty of the mode control element in the resonant cavity of the VECS. The self-injection locking characteristic of the microcavity device in the linewidth narrowing element is used to narrow the output linewidth of the laser, which can achieve a deep narrowing of the laser linewidth and realize ultra-narrow linewidth output.

The invention provides a device and a method for measuring the line width of a laser, which can be applied to the technical field of laser. The measuring device comprises a filter which is configured to have a tunable transmission center wavelength so that the variable quantity of the transmission center wavelength covers the line width of a laser to be measured and filter output laser of the laser to be measured, a transmission spectrum of the filter has a predetermined line type and a predetermined line width, and an output spectrum of the laser has a predetermined line type; the detector is configured to detect the filtered laser to obtain the power of the output laser penetrating through the filter under different penetrating central wavelengths; the processor is configured to fit each transmission center wavelength and the power corresponding to each transmission center wavelength based on a predetermined line type to generate a power spectrum; and based on the line width of the power spectrum and the predetermined line width of the transmission spectrum, determining the line width of the output spectrum of the to-be-measured laser.

This invention discloses a submarine cable acoustic monitoring system based on scattering-type fiber optic fingerprint technology, belonging to the field of fiber optic sensing technology. The system includes a light source module, a transmitting module, a submarine cable fiber optic sensing unit, a dual-balanced detector module, and a signal processing module. In the light source module, the continuous light output from the laser is split into a probe light and a local reference light by a dynamic beam splitter. The probe light is modulated and injected into the submarine cable fiber, and the resulting backscattered Rayleigh light carries acoustic information back. The dual-balanced detector module has a built-in light intensity monitoring unit that monitors the light intensity of the reference light and the scattered light in real time. By comparing the two intensities, it sends a feedback control signal to the dynamic beam splitter, dynamically adjusting the splitting ratio to maximize the interference term intensity coefficient, thereby improving the signal amplitude and sensing sensitivity. This invention solves the problems of limited sensing distance and high laser linewidth requirements in traditional systems, and is suitable for long-distance, high-reliability submarine cable acoustic event monitoring and location in deep-sea environments.

The invention discloses a detection image processing method and device, electronic equipment and a computer readable medium. The processing method comprises the following steps: preprocessing a detection image to obtain a gradient value of each column in the detection image; obtaining a plurality of candidate points and corresponding laser line widths according to the gradient value of each column; selecting a preset number of candidate points as sorting points according to the laser line widths and the peak gray levels of the candidate points; forming connected domains with multiple lengths according to the sorting points meeting the connected domains in each column, and removing the connected domains with the lengths smaller than the noise reduction length; and outputting the final sub-pixel coordinates of the connected domain. The processing method and device for the detection image, the electronic equipment and the computer readable medium have the beneficial effects that the processing method and device for the detection image, which can stably work under high reflection noise, are provided.

This invention discloses a single-frequency pulsed laser with spectral linewidth self-compression based on pulse waveform pre-compensation. The laser comprises a pump source, a pump coupling device, an active fiber, and an output collimator forming a fiber amplifier to amplify the power of a single-frequency pulsed laser output from a single-frequency pulsed seed source with pulse waveform editing capabilities. An isolator protects the single-frequency pulsed seed source with pulse waveform editing capabilities. The laser employs spectral linewidth self-compression based on pulse waveform pre-compensation to optimize the spectral characteristics of the pulsed laser and suppress linewidth broadening during amplification. This laser achieves high peak power and near-Fourier transform-limited linewidth single-frequency pulsed fiber laser output without adding additional laser devices. Furthermore, this technology allows for linewidth tuning through pulse waveform manipulation.

The invention provides a laser linewidth detection method and system in a coherent optical communication system, and the method comprises the steps: S1, receiving a coherent optical signal, carrying out the preprocessing of the coherent optical signal, and inputting the preprocessed signal into a carrier phase recovery module; s2, constructing a line width estimation model according to the signal model of the laser line width; s3, collecting a phase estimation value of a carrier phase recovery module CPR under the known line width and SNR signal-to-noise ratio, inputting the phase estimation value into the line width estimation model, and correcting the line width estimation value; and S4, inputting the phase estimation value of the carrier phase recovery module CPR under any SNR value, and estimating the line width of the laser to be measured. According to the invention, by adopting the phase estimation value of the phase recovery module and using simple mathematical calculation, the estimation of the line width of the laser is realized. According to the method, the estimation deviation under different signal-to-noise ratios is counted by adopting the data sample, so that the accurate estimation of the line width of the laser is realized.

This invention relates to the field of optical communication technology, specifically to a phase noise-insensitive high-order cumulant modulation identification method. The key technical points include the following steps: S1, signal preprocessing; S2, calculating the phase noise-insensitive high-order cumulant of the signal, and constructing two feature parameters based on the phase noise-insensitive high-order cumulant; S3, constructing a modulation format classifier using a decision tree method; S4, inputting the feature values ​​from step S2 into the modulation format classifier constructed in step S3 to determine the modulation format of the signal under test. By addressing the issue that traditional high-order cumulant algorithms are affected by phase noise caused by laser linewidth in optical fiber communication systems, this invention improves the high-order cumulant algorithm, calculates the phase noise-insensitive high-order cumulant value of the signal, constructs two feature parameters based on the phase noise-insensitive high-order cumulant, and finally uses the feature parameters as classification features, inputting them into the decision tree modulation format classifier for classification.

The invention relates to a time-delay self-beat frequency method and device for measuring laser line width. The time-delay self-beat frequency method comprises the following steps: dividing to-be-measured laser into first local oscillation light, second local oscillation light and first signal light; inputting the first signal light into a phase compensation time-delay optical fiber system, enabling the phase compensation time-delay optical fiber system to extract additional phase noise introduced by a time-delay optical fiber by using the first local oscillator light, and performing active noise compensation on the phase noise of the first signal light by using an active locking technology; performing optical frequency mixing on the second local oscillation light and the compensated first signal light; and performing coherent detection on the mixed light of the first signal light and the second local oscillation light by using a balance detector, outputting the mixed light to a spectrum analysis device, and calculating the laser line width according to a spectrogram given by the spectrum analysis device. According to the invention, active noise compensation can be carried out on the phase noise of the first signal light by using an active locking technology, and the influence of factors such as ambient temperature and vibration on laser line width measurement is reduced.

The invention provides a high-accuracy narrow-linewidth laser linewidth measuring system, which can directly quantify 1 / f noise of a delay optical fiber in a traditional delay self-heterodyne linewidth measuring device, and can accurately measure the linewidth of the laser under the condition that the influence of the noise of the laser is controlled to be the same. The thermal noise of the time-delay optical fibers with different lengths is compared by changing the lengths of the optical fibers of the two arms of the interferometer; normalized instantaneous phase noise of a laser is obtained by using a short optical fiber interferometer, and an integral line width spectral line is obtained by performing signal self-correlation and Wiener-Singqin theorem, so that spectral line broadening caused by optical fiber thermal noise introduced by a long optical fiber in a traditional delay self-heterodyne line width measurement method is avoided; the problems that the integral line width is widened and the measurement results of optical fibers with different lengths are inconsistent due to the fact that the measured differential phase noise is influenced by long-fiber noise disturbance existing in a traditional delay self-heterodyne system for a long time are solved, and the line width measurement accuracy of the narrow line width laser is improved.

The invention discloses a chip integrated ultra-narrow linewidth laser based on a micro Fabry-Perot (FP) cavity. The chip integrated ultra-narrow linewidth laser comprises a laser chip, an on-chip reflection conversion loop, a coupling lens and the micro FP cavity, wherein the on-chip reflection conversion loop consists of a waveguide, a first phase shifter, an adjustable coupler, a second phase shifter and a waveguide grating; the core is that feedback light of the FP cavity is purified by utilizing a reflection conversion loop; specifically, laser is divided into two paths through an adjustable coupler in a loop, one path enters a miniature FP cavity, and the other path is reflected by a waveguide grating. Through accurate adjustment, non-resonant light directly reflected from the front end of the FP cavity and reflected light of the waveguide grating are subjected to destructive interference in the direction of returning to the laser chip, so that noise is filtered out, pure FP cavity resonant light is fed back to the laser chip, and the laser line width is narrowed by using the self-injection locking principle. Meanwhile, constructive interference occurs between the two paths of light at the output end, and output of narrow-linewidth laser is achieved.

The application discloses an anti-interference target laser line extraction method, comprising the following steps: S1, Gaussian filtering processing is performed on an image; S2, start and end position points of the target laser line are determined: the start and end position points of the target laser line are b and b1 respectively, a difference value of adjacent two pixel gray values is diffval, and the determination method of b and b1 is as follows: the determination method of b is b-a<=diffval and c-b>=diffval; the determination method of b1 is b1-a1>=-diffval and b1-c1<=-diffval; wherein, a and c are respectively two adjacent points on both sides of b in the width direction of the laser line, and a1 and c1 are respectively two adjacent points on both sides of b1 in the width direction of the laser line; S3, the line width of the target laser line is set; S4, a center point of the target laser line is extracted: the gray gravity center method is used to extract the center of the laser line; and S5, the target laser line is extracted; the application can be applied to a 3D laser profiler to extract a correct laser line under the condition of interference, so that serious loss caused by inaccurate extraction of the laser line to industrial production is avoided. The application improves the laser line extraction precision.

The application discloses a narrow linewidth Raman frequency modulation laser based on a thin film lithium niobate, comprising: a distributed feedback laser serving as a pump light source; and a thin film lithium niobate photonic integrated chip; wherein the thin film lithium niobate photonic integrated chip is sequentially provided with an input coupling waveguide, a lithium niobate micro-ring, a connecting waveguide, a Sagnac reflection ring and an output coupling waveguide; the input coupling waveguide is coupled with the distributed feedback laser, the lithium niobate micro-ring is optically coupled with the input coupling waveguide and the connecting waveguide respectively; the Sagnac reflection ring is connected with one end of the connecting waveguide away from the lithium niobate micro-ring; and the output coupling waveguide is led out from the lithium niobate micro-ring and used for outputting narrow linewidth Raman frequency modulation laser. The application can solve the problems of poor self-injection locking and Raman frequency modulation coordination, low integration, wide laser linewidth and insufficient frequency tuning performance in the prior art, and realizes wavelength transfer and multi-wavelength rapid synchronous tuning of narrow linewidth Raman laser.

This invention discloses an integrated external cavity laser and its usage method, relating to the fields of optical communication and photonic integrated devices. The integrated external cavity laser includes a light source module, a coupling module, and an external cavity module. The coupling module couples the optical signal output from the light source module to the external cavity module. The external cavity module splits the optical signal into two paths to adjust the splitting ratio between the two paths. The external cavity module also returns the mode-selected two paths of light to the light source module via the coupling module. The light source module reflects the optical signal returned from the coupling module, so that the light source module, coupling module, and external cavity module form a closed resonant cavity. This invention can narrow the laser linewidth and improve the side-mode rejection ratio under the performance limitations of existing integrated devices.