29 results about "Fiber optic coupler" patented technology

The application discloses a kind of spectrometer performance calibration devices for frequency domain OCT system, include: two groups of calibration light path components, light source drive board and fiber coupler;Two groups of calibration light path components are connected to fiber coupler;Fiber coupler is connected to light source drive board;Calibration light path component includes: six-dimensional adjustment frame, installation lens barrel, corner cube, optical flat, two-dimensional adjustment frame, collimating lens and collimating adjustment frame;Corner cube is installed to installation lens barrel;Installation lens barrel is connected to six-dimensional adjustment frame;Optical flat is installed to two-dimensional adjustment frame;Collimating lens is installed to collimating adjustment frame;Collimating adjustment frame is equipped with fiber connection part;Two-dimensional adjustment frame is between installation lens barrel and collimating adjustment frame.This application's spectrometer performance calibration device for frequency domain OCT system, simple structure can obtain signal-to-noise ratio with depth variation curve and other performance indicators, judge spectrometer assembly and debugging result, improve instrument consistency.

The application relates to a fiber-optic gyroscope Y waveguide nonlinearity index measuring device, which comprises a light source, a fiber coupler, a measured Y waveguide, a fiber ring, a photoelectric detector, a measurement algorithm operator, a high-linearity voltage signal amplifier, a data collector and an upper computer; wherein the light source, the fiber coupler, the Y waveguide and the fiber ring are sequentially connected; the photoelectric detector is connected with the fiber coupler and the measurement algorithm operator; the high-linearity voltage signal amplifier is connected with the Y waveguide and the measurement algorithm operator respectively; the measurement algorithm operator is connected with the data collector; and the data collector is connected with the upper computer. The application can solve the problems that the Y waveguide nonlinearity index of the fiber-optic gyroscope is difficult to measure and cannot be quantitatively tested, and can effectively evaluate the quantitative relationship between the Y waveguide nonlinearity index and the threshold and scale factor nonlinearity indexes of the gyroscope.

The present application relates to a kind of liquid leakage judgment and leakage location positioning system and method, including the broadband light source, spectrum analysis module and fiber coupler respectively connected on optical fiber circulator, fiber coupler is connected multiple groups of liquid leakage monitoring sensor respectively;Liquid leakage monitoring sensor includes at least two groups of fiber collimator arranged horizontally on the same axis, wherein a group of fiber collimator is connected fiber grating, and float is arranged in the direction perpendicular to the axis of two groups of fiber collimator;Broadband light source generates optical signal, and optical signal is sent to fiber collimator by fiber coupler, and the reflection signal generated by fiber grating is acquired by spectrum analysis module;The bottom of float has opening, and the liquid leakage enters the inside of float by opening and pushes it to rise, and the light path between two fiber collimators is shielded, and reflection signal disappears in spectrum analysis module, and the position of liquid leakage monitoring sensor corresponding to disappeared signal is positioned leakage position.

A Fabry-Perot sensor cavity length demodulation system and a Fabry-Perot sensor cavity length demodulation method. The demodulation system comprises: a first light source (1) emitting light of a first wavelength; a second light source (2) emitting light of a second wavelength; a wavelength division multiplexer (3) receiving light from the first light source (1) and light from the second light source (2); a fiber coupler (4) receiving and coupling light of the first light source (1) and light of the second light source (2); a Fabry-Perot sensor (5) receiving coupled light from the fiber coupler (4) such that the coupled light is reflected at a first plane and a second plane of the Fabry-Perot sensor (5) to interfere and return the interference light to the fiber coupler (4); a demultiplexer (6) receiving the interference light and separating the interference light into a first light beam (L1) and a second light beam (L2); a first detector (7) and a second detector (8) respectively receiving the first light beam (L1) and the second light beam (L2) and transmitting a first interference signal of the first light beam (L1) and a second interference signal of the second light beam (L2) to a processor (9), the processor (9) being configured to obtain and analyze a first curve (S1) of the first interference signal and a second curve (S2) of the second interference signal to determine an inflection point of a physical quantity to be measured causing a cavity length change in the first curve (S1) and / or the second curve (S2), the first curve (S1) being a curve of light intensity of the first interference signal with respect to the cavity length, and the second curve (S2) being a curve of light intensity of the second interference signal with respect to the cavity length.

Systems disclosed herein are directed to optical terminals configured for free space communication comprising at least one lens collector assembly comprising a lens and a dual clad fiber optic coupler attached to the at least one lens, and a transceiver operably connected to the at least one lens collector assembly.

This invention discloses a small, high-precision fiber optic angular acceleration measurement device. The light source module is connected to a fiber optic circulator via a polarizer, and the fiber optic circulator is connected to an optical modulator via a fiber optic coupler. The optical modulator is connected to a polarization-maintaining fiber optic ring, used to split the linearly polarized light into two counter-propagating beams that enter the polarization-maintaining fiber optic ring, and to receive the interference signal returned from the polarization-maintaining fiber optic ring and input it into the fiber optic coupler. The fiber optic coupler splits the interference signal into two outputs: one path enters a first photodetector via the fiber optic circulator, and the other path enters a second photodetector. The first photodetector converts the received optical signal into an electrical signal and inputs it into a first digital signal acquisition processor. The second photodetector converts the received optical signal into an electrical signal and inputs it into a second digital signal acquisition processor. The first and second digital signal acquisition processors respectively acquire and process the input signals and input them into a data processing unit to calculate the angular acceleration value.

This invention discloses a miniature beam-splitting optical path system for atomic interferometry, comprising a main optical path and primary and secondary reflection sub-paths. Laser light is input into the main optical path after purification and polarization, and then split by a half-wave plate and a polarizing beam-splitting prism. The split beam consists of a primary reflection and a secondary reflection generated by the secondary reflection, which passes sequentially through a quarter-wave plate and a 0° mirror and re-enters the polarizing beam-splitting prism. The primary and secondary reflections then enter their respective sub-paths for further splitting. Independently adjustable right-angle prisms and polarizing beam-splitting prisms within the sub-paths eliminate the influence of the incident direction of the light entering subsequent optical paths. This miniature beam-splitting optical path system and method can output multiple laser beams with consistent polarization, adjustable power and frequency. It can be input and output via fiber optic couplers, and is suitable for atomic interferometry and other fields. It improves the efficiency of laser energy utilization and the stability of laser parameters, easily maintains symmetrical optical path distribution, and enhances system integration.

This invention discloses an experimental method for measuring the electron-hole recombination emission rate. The apparatus for this method includes a laser chip (with an anti-reflection coating on only one end of its horizontal two-sided end face), a plano-convex lens, a polarizer, a fiber optic coupler, an optical fiber, and a spectrometer. The plano-convex lens, polarizer, plano-convex lens, and fiber optic coupler are placed sequentially on the same horizontal line on both sides of the chip. The fiber optic coupler is connected to the spectrometer via an optical fiber. First, energy is applied to the laser chip, causing it to emit light from both sides. The spectra from both sides are focused onto the fiber optic coupler by the plano-convex lens and then transmitted to the spectrometer via the optical fiber. By rotating the polarizer, different polarization spectra can be selected to obtain specific spectral images under transverse electric / magnetic field modes. Finally, by substituting the spectral data from both ends into the established formula, the electron-hole recombination rate of the laser chip can be calculated.

This invention specifically relates to a refractive index measurement system and method based on fiber optic interferometry, used for real-time monitoring of the refractive index of transparent gases and liquids. It addresses the technical problems of existing air refractive index measurement methods, which either struggle to accurately obtain the absolute value of the refractive index, or involve complex procedures, cumbersome optical path adjustments, susceptibility to vibration interference, and low dynamic response speed. The fiber optic interferometry-based refractive index measurement system includes a tunable fiber laser, a first fiber coupler, a transmitting probe, a receiving probe, an attenuator, a second fiber coupler, a photoelectric converter, and a recording device. The first fiber coupler splits the optical signal emitted from the tunable fiber laser into two paths, one input to the transmitting probe and the other to the attenuator. The input of the second fiber coupler is connected to the output of the attenuator and the output of the receiving probe. This invention offers high reliability and a fast response time of 0.2 ms; it can perform refractive index monitoring in various scenarios.

The application relates to a miniaturized near-infrared spectrometer imaging system, and relates to the field of near-infrared spectrometers, which comprises a light source module, a sample light line generation module, a fiber coupler, a fiber F-P filter, a photodetector and a multimode optical fiber; the light generated by the light source module can irradiate a sample through the sample light line generation module and generate sample light lines; the fiber coupler and the fiber F-P filter are connected through the multimode optical fiber, and the fiber F-P filter and the photodetector are connected through the multimode optical fiber; the fiber coupler receives the sample light fiber and transmits the sample light fiber to the photodetector through the multimode optical fiber, the fiber F-P filter and the multimode optical fiber. The application has the effects of reducing the baseline drift and noise of the spectrum, improving the accuracy of the spectrum, and being smaller in size and lighter in weight.

A fiber optic coupler includes a coupler housing, an inner housing for releasably receiving a fiber optic connector, a release sleeve, and a retainer. The release sleeve is mounted to the inner housing within the coupler housing and is translatable within the coupler housing between a first position and a second position. The retainer is moveably mounted to the inner housing and engaged with the release sleeve, wherein movement of the release sleeve from the first position to the second position causes the retainer to move radially relative to the inner housing from a locking position to an unlocking position to release the fiber optic connector.

The application provides a near-earth optical communication turbulence suppression system and method based on emission source gain regulation, which comprises a host computer and a slave computer, and each comprises a space-fiber coupler, a PSD position detector, a PSD demodulation and control assembly, a communication transmitter-receiver, an electrically-controlled optical attenuator, a stepping actuator and a beacon light emitter; the space-fiber coupler aligns and matches the emitted light with the receiving field of view and couples the space light to the optical fiber; the beacon light emitter emits service beacon light; the PSD position detector performs real-time position detection on the light spot of the service beacon light; the PSD demodulation and control assembly calculates the off-target amount of the light spot position of the service beacon light and its control amount output to the stepping actuator, demodulates the service beacon text data and transmits it to the communication transmitter-receiver; the electrically-controlled optical attenuator regulates the emitted light power of the communication transmitter-receiver; and the communication transmitter-receiver controls the voltage value of the electrically-controlled optical attenuator based on the service beacon text data to realize closed-loop gain control and turbulence suppression from the receiving end to the transmitting end.

The invention discloses a compact broadband frequency modulation optical fiber AOM optical path, which comprises an optical fiber coupler I, a 1 / 2 wave plate and a polarization splitting prism, the 1 / 2 wave plate and the polarization splitting prism are rotatably arranged in front of the optical fiber coupler I in sequence, and an AOM crystal, a rotatably arranged 1 / 4 wave plate, a separation blade and a spherical reflector are sequentially arranged on an optical path separated by the polarization splitting prism. The sphere center of the reflecting surface of the spherical reflector is located in the center of the AOM crystal, and a second optical fiber coupler is arranged on the other light path separated by the polarization splitting prism. According to the optical fiber AOM optical path scheme provided by the invention, a broadband frequency modulation optical fiber AOM optical path is simplified, the optical path is shortened by 1 / 3, miniaturization is further realized, and the optical fiber AOM optical path is more compact, has higher implementability and meets the use requirements of a miniaturized all-optical fiber laser optical path.

The invention provides a film thickness measuring device and method based on high-precision frequency domain broadband light interference. The film thickness measuring device comprises a light source (1), an optical fiber coupler (2), a spectral analysis module, a detection arm and a signal processing module used for signal acquisition. Light emitted by the light source is output by the optical fiber coupler, sequentially passes through the collimating lens (3) and the focusing microscope objective (4) at the detection arm and then is divided into two paths at the spectroscope (6); one path of light is reflected to the silicon wafer (5) of the reference arm by the spectroscope and then is reflected back to the spectroscope; the other path of light is reflected back to the spectroscope after transmitting out of the spectroscope to irradiate a sample (7); the two paths of light converge at the spectroscope and interfere with each other, the generated interference light is returned by the optical fiber and then is collected by the spectral analysis module, and the collected data is transmitted to the signal processing module; according to the invention, the resolution of the optical coherent thickness measurement system can be significantly improved, and the application range and potential of the low-coherence interference thickness measurement system can be effectively expanded.

Some embodiments of the present disclosure are directed to mechanical couplers for fiber array units (FAUs) and methods of manufacturing the same. For example, an optical connector for an optical device may include an FAU and a receptacle positioned on the optical device. The FAU may include a plurality of fiber couplers (e.g., v-grooves, u-grooves, and / or the like) into which optical fibers (e.g., single mode fibers) may be positioned and held in place (e.g., using an adhesive). The FAU may be formed from a substrate, and the fiber couplers may be formed in a surface of the substrate. The FAU may also include substrate mechanical couplers (e.g., additional v-grooves, u-grooves, and / or the like) formed in the surface of the substrate adjacent the fiber couplers and extending substantially parallel to the fiber couplers on the surface of the substrate.

An apparatus, system, and method for providing an optical coupler. The optical coupler can be a micro fiber optic coupler that can include: a housing having a size less than 4 mm x 4 mm; an input end into the housing, the input end capable of receiving a fiber optic transmission line; a transmission line prism within the housing having a size less than 2 mm x 2 mm, the transmission line prism in optical communication with the transmission line; a receiving line prism having a size less than 2 mm x 2 mm, in optical communication with the transmission line prism at a corresponding angle in a range of 30 to 60 degrees, and capable of receiving a signal entering on the transmission line and redirecting the received signal; and a receiving line in optical communication with the receiving line prism and capable of receiving and outputting the redirected received signal.

The application relates to a fluorescence detection device and a crystallization state detection system, the fluorescence detection device comprising a pulsed light signal source, a fiber coupler and a fluorescence detector; the pulsed light signal source comprises at least two signal output ends for outputting pulsed light signals of different frequencies, one of the at least two signal output ends is connected with the fiber coupler through a first optical fiber, and the other signal output ends are connected with the fiber coupler through a delay unit; the delay unit is used for generating a delay between the pulsed light signals of different frequencies; the fluorescence detection device utilizes the delay unit to make the fiber coupler output light signals of different frequencies, i.e. combined wave signals, after coupling, so as to realize detection of different depths of a sample to be detected by utilizing the combined wave signals of different frequencies in time sequence, and improve the detection comprehensiveness.

The invention relates to a sensor as well as a preparation method and a measurement method thereof, in particular to a fiber-optic gyroscope based on a 3 * 3 coupler as well as a preparation method and a measurement method thereof, and aims to solve the problems of lower bandwidth, limited measurement range or higher cost of the conventional fiber-optic gyroscope. The fiber-optic gyroscope comprises a fiber-optic gyroscope table body, a fiber-optic ring fixing cavity arranged on the fiber-optic gyroscope table body, and a combined body of a main fiber-optic ring and a cushion fiber layer ring which are arranged in the fiber-optic ring fixing cavity, the device further comprises an erbium-doped optical fiber light source, a 2 * 2 single-mode optical fiber coupler, an integrated optical modulator, a first photoelectric detector, an optical fiber isolator, a 3 * 3 single-mode optical fiber coupler, a second photoelectric detector and a third photoelectric detector. The method has the advantages that the assembly space of the gyroscope is greatly saved, and meanwhile, the cost of the backup fiber-optic gyroscope is also reduced; and the length and the diameter of the optical fiber ring of the gyroscope for stripe correction can be flexibly adjusted according to actual use requirements.

This invention discloses a high signal-to-noise ratio (SNR) performance enhancement system based on BOTDR, relating to the field of distributed fiber optic sensing technology. It includes an optical path unit and a circuit processing unit. The optical path unit comprises a narrow-linewidth laser (Laser), a pulse modulation module, a variable optical attenuator (VOA), a hierarchical optical amplification module, an optical circulator (OC), a polarization scrambler (PS), and a fiber coupler array. The circuit processing unit includes a photodetector pre-amplifier module, a low-noise amplifier, a frequency mixer and down-conversion module, and a frequency selection module. This BOTDR-based high SNR performance enhancement system significantly improves the system's SNR and monitoring accuracy through optimized optical path and circuit structure design, precise selection of core optical components, and innovative optical signal processing links. Through an integrated design of 1550nm band narrow-linewidth continuous optical modulation, hierarchical precise amplification, polarization state optimization, and efficient coherent beat frequency, noise in the Brillouin scattering signal is effectively suppressed during transmission and detection, resulting in a significant improvement in signal strength.

The application discloses a method for correcting error of homodyne symmetrical demodulation by fitting an ellipse in space, which comprises the following steps: taking three-way output data of a fiber 3X3 coupler as a whole of three-dimensional ellipse, fitting a general equation of the plane where the ellipse is located by using a least square method, establishing a new three-dimensional coordinate space by using the plane and its normal line, converting the original three-dimensional coordinate space ellipse into the new three-dimensional coordinate space, obtaining a two-dimensional plane ellipse, fitting a general equation of the two-dimensional plane ellipse by using the least square method, obtaining fitting coordinates of the original three-dimensional space ellipse by using the relationship between the new and old three-dimensional coordinate spaces, and obtaining direct current component, alternating current component coefficient and phase error of the three-way output data by using the maximum and minimum values of three components of the fitting coordinates of the original three-dimensional space ellipse, so as to correct error of homodyne symmetrical demodulation calculation. The application is different from the traditional method of processing two-way output data, and can more objectively obtain system error of a fiber sensing system and is less affected by system random noise.

This invention provides a laser synthesis wavelength measurement interferometer based on optimized fiber coupling. The interferometer includes: a composite laser source, a fiber coupler assembly, a fiber beam splitter assembly, a polarization beam splitter assembly, an adjustable optical path reference fiber, an adjustable optical path measurement fiber, a photodetector assembly, and an electronic control system, all interconnected. The composite laser source emits two laser beams with wavelengths λ1 and λ2 respectively. The fiber coupler assembly includes a first fiber coupler, a second fiber coupler, and a third fiber coupler. The fiber beam splitter assembly includes a first fiber beam splitter and a second fiber beam splitter. The polarization beam splitter assembly includes a first polarization beam splitter and a second polarization beam splitter. The photodetector assembly includes a first photodetector, a second photodetector, and a third photodetector. This invention improves the measurement accuracy of the interferometer, and damaged parts of the interferometer can be replaced individually, facilitating maintenance by repair personnel.

The invention discloses a GHz high repetition frequency active mode-locking fiber laser and an engineering manufacturing method thereof, and the laser employs an innovative optoelectronic isolation layered architecture, and comprises a temperature control layer, an optical layer and an electrical layer which are sequentially arranged from bottom to top. The optical layer comprises an optical fiber wavelength division multiplexer, a gain optical fiber, an electro-optic phase modulator, an optical fiber isolator and band-pass filter integrated device and an optical fiber coupler; the electrical layer comprises a modular microwave source, a pumping laser source, a printed circuit board, a photoelectric detector and a cooling fan; the temperature control layer comprises a TEC refrigeration sheet and a heat conduction copper block. Through precise layered temperature control design, distributed multiple sensors, multi-TEC partition cooperative control, integrated mechanical structure optimization and component type selection layout adaptation, the technical problems that a traditional active mode-locked laser is large in size, poor in environment anti-interference performance and low in temperature stability are solved, high-uniformity and high-stability GHz high-repetition-frequency laser output is achieved, and the application range of the active mode-locked laser is widened. And engineering large-scale production and application are facilitated.

The invention relates to the technical field of laser welding, and provides a fusion depth monitoring system and method based on an OCT automatic following laser welding focal plane, and the system comprises a light source, an optical fiber coupler, a sample arm, a reference arm, a spectrometer and a data processing module; the light source is used for generating broadband low-coherence light; the optical fiber coupler is used for splitting the broadband low-coherence light into sample arm light and reference arm light, and synthesizing the returned sample arm light and reference arm light into an interference light signal; the sample arm is used for guiding and focusing the sample arm light to a target area in the laser welding process to form returned sample arm light; the reference arm is used for reflecting the reference arm light through a reflection assembly to form returned reference arm light; the spectrograph is used for carrying out spectrum analysis on the interference light signal; the data processing module is used for calculating the welding penetration depth in real time according to the spectrum analysis result. According to the invention, through integration of the high-response linear motor and the closed-loop control algorithm, rapid matching of the optical path of the reference arm is realized.

The invention discloses a Doppler laser radar frequency locking system and method. The system comprises a laser emission system, a polarization control system, a photoelectric receiving and frequency discrimination system and a feedback control and monitoring system. According to the system, a tunable pulse laser, a narrow-band filter, an optical fiber coupling mirror, an optical fiber and an optical fiber collimator are used for realizing laser emission, and polarization state purification of a laser signal and dual-channel equal-ratio light splitting of a frequency discriminator are realized through a polarization control system; a dual-channel Fabry-Perot etalon (DFP) is adopted as an optical frequency discriminator to detect laser frequency deviation, a frequency response value R is calculated according to a transmittance frequency spectrum of the dual-channel Fabry-Perot etalon and serves as a frequency discrimination reference of a feedback control and monitoring system, a closed loop of a frequency locking system is completed, and the frequency deviation is detected. And meanwhile, the real-time locking state and the frequency stability of the laser frequency are monitored. The invention overcomes the defects of inconsistency between frequency locking and frequency discrimination systems, poor detection precision, complex system and the like caused by dependence on molecular absorption cells (such as iodine molecules and the like) and a reference light path in the existing Doppler laser radar frequency locking application, and has the technical characteristics of integration of frequency locking and frequency discrimination, wide frequency locking range, miniaturization, no wavelength limitation and the like; and high-precision real-time locking of the laser frequency and the frequency discriminator can be realized.

This invention discloses a hybrid optoelectronic feedback laser based on Fano resonance within a crystal whispering cavity. It includes a primary laser, whose emitted optical signal sequentially passes through a fiber optic circulator and a fiber optic coupler. The optical signal output from the fiber optic coupler is split into two beams. One beam is transmitted to the laser output end, while the other enters a prism-crystal-cavity coupling system to generate Fano resonance. The Fano optical signal output from the prism-crystal-cavity coupling system is split into two paths. One Fano optical signal returns to the fiber optic circulator via a fiber delay line and is re-injected into the primary laser; this feedback loop is the optical feedback loop. The other Fano optical signal passes through a photodetector to generate an error electrical signal for active frequency locking. This signal is then sent to a PID servo controller, and the signal after passing through the PID servo controller is sent back to the primary laser, forming an electrical feedback loop. This laser exhibits high feedback signal strength, a simple overall system structure, low noise, and high reliability.

The utility model provides an ophthalmology measuring system with a double-optical-wedge prism group, which realizes efficient and accurate ophthalmology OCT (optical coherence tomography) imaging. The system comprises an OCT imaging module which comprises an OCT light source, a reference arm module, an OCT sample arm module, an optical fiber coupler and a detector. The sample arm module is integrated with an optical path switching scanning device and can guide detection light to a posterior segment or anterior segment optical path. A double-optical-wedge prism group is introduced and comprises a fixed prism and a movable prism, and the movable prism can translate relative to the fixed prism to dynamically adjust the optical path. The design is combined with the Doppler frequency shift technology, the detection depth of the system is remarkably enhanced, meanwhile, the imaging resolution is kept, and high-cost equipment does not need to be additionally added. The system can rapidly switch imaging modes, realizes accurate imaging of different parts of the eyes, improves the measurement speed and accuracy, reduces the cost, and is suitable for clinical ophthalmic diagnosis.

The invention provides a fiber bragg grating wavelength demodulation device based on double Sagnac rings, and the device comprises a pulse light source which is configured to emit detection pulse light; the fiber bragg grating is configured to reflect a specific light component in the reflected light to generate reflected light corresponding to the specific light component; a first optical fiber coupler configured to split the reflected light into first and second light beams; the first Sagnac ring and the second Sagnac ring are respectively configured to filter the light beams so as to generate first filtered light signals and second filtered light signals, relative wavelength displacement exists between transmission spectrums of the first filtered light signals and the second filtered light signals, and optical path difference exists between output optical paths of the first filtered light signals and the second filtered light signals; a photoelectric detector configured to convert the filtered optical signals to generate analog electrical signals; an analog-to-digital converter configured to convert the analog electrical signal into a digital electrical signal; and the signal processing module is configured to demodulate the Bragg wavelength drift distance of the fiber bragg grating based on the intensity relationship between the two paths of sampling values processed by the first optical fiber coupler in the digital electric signal.

The utility model belongs to the field of optical fiber couplers, and relates to a waterproof optical fiber coupler, which comprises an optical fiber plug and an optical fiber socket, the optical fiber plug and the optical fiber socket are respectively connected with an optical fiber cable, two sides of the optical fiber plug are connected with clamping units, and each clamping unit comprises a fixed seat and a sliding rail which are fixedly connected with the optical fiber plug. The sliding rail is slidably connected with a sliding seat, the fixed seat is rotatably connected with a rotating rod, the rotating rod is in threaded connection with the sliding seat, the two sides of the optical fiber socket are fixedly connected with screw hole seats, one end, corresponding to the rotating rod, of each screw hole seat is provided with a threaded hole, and the upper end of the fixed seat and the upper end of the sliding seat are provided with clamping plates. The clamping plate is provided with a clamping groove used for positioning an optical fiber cable.

An Er: YAG composite optical fiber laser based on nonlinear polarization rotation mode locking comprises a pumping source and an optical fiber annular resonant cavity, and the optical fiber annular resonant cavity is formed by connecting a wavelength division multiplexer, an Er: YAG composite optical fiber, an extrusion type polarization controller, a polarization dependent optical fiber isolator, a three-ring rotation type polarization controller and an optical fiber coupler through single-mode optical fibers. The pumping source is connected with the pumping end of the wavelength division multiplexer, and stable mode-locked laser pulses are output through 20% of the output end of the optical fiber coupler; or the optical fiber annular resonant cavity is formed by sequentially connecting a wavelength division multiplexer, an Er: YAG composite optical fiber, an optical fiber coupler, an extrusion type polarization controller, an optical fiber polarizer, a three-ring rotary type polarization controller and a polarization independent optical fiber isolator through optical fibers; an extrusion type polarization controller, an optical fiber polarizer and a three-ring rotary type polarization controller jointly achieve an artificial saturable absorber equivalent to nonlinear polarization rotation, and passive mode locking is achieved. The antenna has the advantages of ultra-wide gain spectrum, strong anti-interference capability and the like.