832 results about "Fiber ring" patented technology

A single-frequency Brillouin fiber ring laser with extremely narrow linewidth comprises a single-frequency narrow-linewidth rapid-tunable pump laser, a temperature-controlled acoustically-damped package for Brillouin fiber ring laser cavity, and an auto-tracking feedback electronic loop with novel configuration for active stabilization. The Pound-Drever-Hall frequency-locking technique is employed to keep pump laser frequency in resonance with one of the Brillouin fiber ring cavity modes. Instead of changing cavity length of Brillouin fiber ring laser, the pump laser frequency is rapidly tuned in the auto-tracking feedback electronic loop. This enables extremely narrow linewidth radiation emitted from a Brillouin fiber ring laser without stretching the fiber ring. Dual-wavelength actively stabilized Brillouin fiber ring laser may be generated from a single ring cavity by polarization-combining or wavelength-combining two pump laser beams and using two independent feedback loops to the two operation wavelengths.

A fiber optic network transmits data between a hub node and a plurality of local nodes connected by at least one unidirectional fiber ring. Downstream data streams are carried on wavelength-division-multiplexed optical carriers from the hub node to the local nodes. An optical carrier corresponding to a specific wavelength carries downstream data streams to a specific local node. Downstream data streams are multiplexed onto an optical carrier via orthogonal frequency division multiplexing. A parallel signal detector in each local node detects all downstream optical carriers. A signal processing module demultiplexes the data stream from the optical carrier having the specific wavelength corresponding to the local node. An upstream data stream is multiplexed via orthogonal frequency division multiplexing onto an upstream optical carrier having the same specific wavelength and transmitted from the local node to the hub node. Upstream data awaiting transmission is allocated to specific subcarriers and time slots.

A passive optical network. The optical network has an optical fiber ring with ends terminating at an optical line terminal. The optical line terminal transmits signals through the fiber ring to optical network units passively connected to the fiber ring. The optical network units receive signals from the optical line terminal through the fiber ring. In one embodiment, the optical line terminal transmits redundant signals in opposite directions through the fiber ring and the optical network units receive the redundant signals from opposite directions through the fiber ring. In another embodiment, the optical network units receive TDM signals from and transmit TDMA signals to the optical line terminal through a fiber line. A first WDM coupler passively connected to the fiber line multiplexes an overlay signal with at least one of the TDM signals and the TDMA signals for transmission through the fiber line. The overlay signal has a wavelength different than the signals with which it is multiplexed.

A ring laser includes a large-core rare-earth-doped fiber ring-connected with a free-space path having an electro-optic switch, output coupler, and intracavity band-pass filter to enforce lasing operation in narrow wavelength range. In some cavity-dumped modes, the laser is configured in a similar manner, except that an output coupler is omitted since the optical power is extracted from the laser cavity by the electro-optic switch itself. The same laser can be configured to operate in Q-switched and / or cavity-dumping modes as well as in hybrid modes (e.g., partial Q-switch, followed by cavity dumping, or even CW). In some embodiments, the laser can be used as, or inject laser light into, a regenerative solid-state amplifier, or a Raman laser, or can be also used to generate visible, ultra-violet, mid-infrared, and far-infrared (THz) radiation via nonlinear wavelength conversion processes. The various embodiments can use a power oscillator or seed-plus-amplifier MOPA configuration.

The invention discloses an FOG based on neural network to do temperature compensation, using the neural network learning algorithm for the temperature drift compensation method, and the temperature compensation method obtains the amendment temperature compensation coefficient to provide parameters for FOG high precision output. According to the effect of the temperature to the FOG output when the FOG working, it respectively installs a temperature sensor A on the light source, a temperature sensor B at the Y waveguide, a temperature sensor C at the fiber ring inside and a temperature sensor D at the fiber ring outside, and through temperature change of the four temperature sensors, and using the neural network learning algorithm for temperature compensation model training, it makes the built temperature drift compensation having good nonlinear mapping ability, self-learning ability and the generalization ability; the temperature drift compensation coefficient measurement is measured in the debugging phase, reducing the gyro computing volume when using.

The invention enables protection of a ring frame transferred via an inter-ring bridge ring node when a fault occurs at the node in a multiring. Ring nodes form a ring protection domain to enable one ring node to be bypassed by using other ring nodes when a fault occurs at this ring node. The TTL value of ring frame to be transferred through the bypass is set to a value obtained by adding the number of hops h to the faulty ring node to a common initial value A in the same two-fiber ring to enable detection of a characteristic TTL value at a bypassing ring node. The bypass fur the ring frame is selected with reference to the characteristic TTL value at the bypassing ring node.

This invention discloses one fiber sensor to measure liquid temperature and reflection rate, wherein, the device comprises transparent and reflection types; the transparent device comprises wide band light source with out end connected to the sensor of temperature ad reflection rate with output end connected to the wave length modulation device; the transparent fiber temperature and reflection rate sensor comprises fiber Brag grating, single mode input fiber and fiber without fiber and output fiber; the reflection device comprises fiber ring device connected to wide band source, wave length demodulator and reflection temperature and reflection rate sensor.

The invention relates to a nano electrostatic spinning and staple fiber ring spinning integrated yarn forming method, and belongs to the technical field of textile processing. The method comprises the following steps: arranging an electrostatic spinning apparatus between each yarn guide hook of a ring spinning frame and a front roller jaw formed by a front roller corresponding to the yarn guide hook and a front rubber roll, enabling a receiving surface of the electrostatic spinning apparatus to stay on a same plane with a public tangential surface of a front leather roll and the front roller at the front roller jaw, forming an electrostatic spinning area between an electrostatic spray head and a receiving surface of a receiving plate, and combining and twisting a nano fiber net spun out from the electrostatic spray head and staple fiber strands passing by the receiving surface of the receiving plate. According to the method, the electrostatic spinning and a conventional ring spinning are reasonably integrated, so that the high-speed successful production of nano fiber yarns is guaranteed, the naon fiber net effectively captures exposed fibers and improves the winding tightness, and the yarn forming structure and performance quality of the nano fiber wrapped blended yarns can be greatly improved. Equipment involved in the method is universal, and the operation and the use are convenient.

The invention relates to a measuring method of the quality of optical fiber ring, used in an optical fiber gyroscope, and a and measuring device thereof; the measuring method and the measuring device belong to the technological field of optical measurement and optical fiber sensing. The method includes the following steps: exerting radial and axial temperature excitation on the optical fiber ring (constant power heating, periodic power heating or non-periodic power heating); measuring the characteristics of the transient temperature of the optical fiber ring; acquiring the test signals of the characteristics of the transient temperature of the optical fiber ring; analyzing and processing the collected data according to the numerical value simulation result of three-dimensional mathematical model of the optical fiber ring; and acquiring the equivalent but asymmetric information of the quantized optical fiber ring which is wound in the radial and axial directions. The device comprises a measuring light source, an optical device which has three ports, a Y wave guide, an optical detector, a signal generator, an electric signal amplification circuit, a controllable heating device, a control circuit and a set of controlling and calculating software. The measuring method can accurately, conveniently and rapidly measure the quality of temperature symmetry of the optical fiber ring, but also can determine the dynamic characteristics of the optical fiber ring without installing the finished product of the optical fiber gyroscope. Thus the measuring method is conducive to the mass production and measurement of the optical fiber ring.

The invention relates to a heat-insulating and vibration-proof framework for an optical fiber gyroscope and a manufacturing method thereof as well as a method for packaging an optical fiber ring. The framework for the optical fiber gyroscope comprises a framework body consisting of an outer wall, an inner wall and a groove bottom; an annular groove is an opening cavity used for mounting the optical fiber ring; the inner side surface and the bottom surface of the annular groove are provided with flame-retardant and heat-insulating and vibration-proof material layers; the material layers are coated with adhesive layers; the adhesive layer at the groove bottom is provided with a lower vibration-proof gasket; an upper vibration-proof gasket is further arranged at the opening at the upper part of the annular groove; the end face of the opening of the annular groove is provided with an optical fiber gyroscope top cover. The manufacturing method comprises the steps of: manufacturing the framework body; processing the flame-retardant and heat-insulating and vibration-proof material layers; coating the adhesive layers and paving the vibration-proof gaskets. The framework for the optical fiber gyroscope has the advantages that the environment temperature and the vibration influence are avoided, framework deformation and a series of errors of the optical fiber gyroscope caused by contact thermal conduction are also avoided, the environment adaptability of the gyroscope is improved, the service life is prolonged; the framework manufacturing method and the method for packaging the optical fiber ring are easy to operate, low in cost, high in efficiency, and stable and reliable in quality.

The invention discloses an all-fiber current sensor consists of a 3x3 polarization-maintaining fiber coupler. One embodiment of the invention, a straight-through type interferometric all-fiber current sensor, comprises a light source, a 3x3 polarization-maintaining fiber coupler, fiber polarizers, a 1 / 4 fiber wave sheet and a transduction fiber ring. The light source is connected with one end of the 3x3 polarization-maintaining fiber coupler; the two ports of the 3x3 polarization-maintaining fiber coupler are respectively connected with two fiber polarizers; and the other ends of the two fiber polarizers are respectively connected with the transduction fiber ring by the 1 / 4 fiber wave sheet; one port of the 3x3 polarization-maintaining fiber coupler is vacant; and the rest two ports of the 3x3 polarization-maintaining fiber coupler are respectively connected with a signal processor by two photoelectric detectors. In addition, another embodiment of the invention, a reflection type interferometric all-fiber current sensor, also uses the 3x3 polarization-maintaining fiber coupler. The all-fiber current sensor avoids phase differences made artificially and makes the current transduction system woke more stably.

The invention provides a few-mode fiber mode coupling measurement device based on a two-photon lantern and a few-mode fiber circulator and belongs to the technical field of fiber characteristic measurement. The few-mode fiber mode coupling measurement device is composed of a light source, a photon lantern A, a few-mode fiber circulator, a measured fiber, a photon lantern B, a photoelectric detection module and a signal processing module. An optical pulse signal generated by the light source is subjected to spatial mode conversion through the photon lantern A to output a designated single stimulus mode, combined with the single-way transmission characteristics of the few-mode fiber circulator, the stimulus mode enters the measured fiber through the few-mode fiber circulator, a backward Rayleigh scattered light generated by coupling the stimulus mode in the measured fiber and the stimulus mode to the non-stimulus mode enters the photon lantern B through the few-mode fiber circulator for spatial model demultiplexing and being output from a corresponding mode port, and the output backward scattered light of each path is subjected to photoelectric detection and data processing, so that the measurement of the few-mode fiber mode coupling coefficient is achieved.

The double-ring coupled all optical buffer storage based on 3x3 fiber coupler stores light signal has its read / write operation under control of one other light signal. Two side ports of the 3x3 fibercoupler constitute the double-ring structure via fiber feedback and the middle ports are used as the input and output of the buffer storage. Control light is led in and led out one fiber ring via twoWDM fiber coupler, and the phase difference between the two ring light signals is altered by means of cross phase modulation effect to realize the write-in and real-out of light signal in fiber ring.The control light signal may be positive logic one or negative logic one. If necessary, light amplifier may be added into the fiber ring for power compensation. Several buffer storages can be constituted into one parallel signal light buffer storage.

The invention discloses an online detection device and method for polarization axis alignment in the direct coupling process of a polarization-preserving fiber ring and a Y waveguide. The polarization axis online detection device comprises a polarization axis detection device and an image processing module. The polarization axis detection device comprises an illumination system, an imaging system and a CCD camera. The imaging system comprises a reflective optical element and an objective lens, and is used for imaging and magnifying the end face of the Y waveguide and the end face of a tail fiber assembly of the tail the polarization-preserving fiber ring. The method comprises the steps that (1) the Y waveguide and the tail ring assembly of the polarization-preserving fiber ring are mounted, and the end face of the Y waveguide and the end face of the tail ring assembly of the polarization-preserving fiber ring are adjusted to be in parallel; (2) the imaging system is adjusted to enable the CCD camera to obtain a clear image; (3) the image is collected to a memory, and the deviation angle of the polarization axis of the Y waveguide and the fiber polarization axis of the polarization-preserving ring is acquired and calculated. According to the online detection device and method, the relative position information of the polarization axes of the polarization-preserving ring and the Y waveguide in the direct coupling process can be acquired in real time, quantitative evaluation can be made for the final state of the alignment of the polarization axes, and a foundation is laid for further improving the axis alignment precision.

Transmissions over a unidirectional optical fiber coupling multiple nodes are compensated for temperature-induced effects. A round-trip delay time is determined for a signal sent from a first node to travel around the unidirectional optical fiber loop and be received back at the first node. That measured round-trip delay time is then used to account for temperature-induced effects on signal transmissions over the unidirectional optical fiber loop. This temperature compensation is particularly beneficial in applications that require a high level of timing accuracy.

The invention discloses a time division multiplexing optical fiber sensing method and a device thereof, relates to an optical sensing method and a device thereof and overcomes the drawback of the wavelength division multiplexing optical fiber sensing demodulation technology of complicated wavelength demodulation equipment due to the use of different central wavelengths of optical fiber sensors and a small number of configured optical sensors due to the bandwidth limitation of the system. The method comprises: a semiconductor optical amplifier generates a pulse optical signal which enters a sensor array; the pulse optical signal is sequentially reflected by all sensors back to the semiconductor optical amplifier, and the opening and closing time of the semiconductor optical amplifier is controlled to allow an optical signal reflected back by a certain sensor to pass through selectively; and the measurement of a selected sensor is realized. The device comprises the semiconductor optical amplifier, a pulse signal generator, a wavelength measuring block, an optical fiber ring and a plurality of sensors, wherein the sensors, the wavelength measuring blocks and the pulse signal generator are communicated with a reflected signal input end, an amplified signal output end and a controlled end of the semiconductor optical amplifier respectively.

The invention is comprised of communication devices designed to provide an array of communication services from network systems to a residential or business consumer through broadband wireless communications. The invention provides a diverse mixture of communication services by utilizing a media access control (MAC) and asynchronous time division multiplexing technique. The invention uses a time slotted transmission scheme where data from communication services are multiplexed according to their delivery requirements which include bandwidth, delay and loss requirements. The invention primarily is comprised of a subscriber unit system and a base station system. The base station system is connected to network systems by a metropolitan fiber ring or terrestrial microwave system using SONET and / or ATM / optic protocols. A base station provides the communication service to the consumer by; 1) receiving a request for a communication service over a wireless transmission link; 2) in response to receiving the request, dynamically configuring a media access control layer in a wireless transmission link for the requested communication service; and 3) generating and transmitting an instruction to provide the requested communication service over the wireless transmission link using the dynamically configured media access control layer.

The invention relates to a fiber grating Fabry-Perot (F-P) cavity vibration sensor and a vibration measurement system thereof. The invention is technically characterized in that a fiber grating F-P cavity is stuck to the middle position of a cantilever beam; and one end of the cantilever beam is fixed on a support, and the other end thereof is connected with a mass block. The measurement system using the vibration sensor is characterized in that one side of the intensity-demodulation type fiber grating F-P cavity vibration sensor is extended into a fiber index-matching liquid, and the other side thereof is connected with the port of a terminal B of a fiber circulator via single-mode fiber; a terminal A of the fiber circulator is connected with a narrow-band light source; and a terminal C of the fiber circulator is connected with a photoelectric detector. By adopting the fiber grating F-P cavity, optical signals can resonate in the F-P cavity to form interference peaks, so that the accuracy of the detection can be greatly increased; meanwhile, by adopting the intensity-demodulation manner of narrow-band light source irradiation, the detection frequency of the vibration sensor can be increased from a few hertz to hundreds of hertz; and the invention can measure the frequency and amplitude of weak vibration signals at the same time, and improve the measurement accuracy.

The invention discloses a laser line width measuring system and method based on an electro-optic modulator and an adjustable radio source. The system comprises a to-be-measured laser, an opto-isolator, a 2*2 optical fiber coupler, an integrated photoelectric detector, a spectrum analyzer and a frequency shift fiber ring. The frequency shift fiber ring is connected between an output port D and an input port C of the 2*2 optical fiber coupler and at least comprises a frequency shifting device and an optical fiber delay line, wherein the frequency shifting device is composed of the electro-optic modulator and the adjustable radio source. The adjustable radio source is used for providing radio driving signals with the adjustable frequency shifting amount for the electro-optic modulator, and the frequency shifting amount can be adjusted in real time by controlling the modulation frequency injected into the electro-optic modulator by the adjustable radio source. The frequency shifting amount can be increased, the adjustable band width range is enlarged to 10 GHz, and the line width measurement limit reaches 1 Hz.

A fiber optic ring interferometer, such as an interferometric fiber optic gyro (IFOG), with a sensing loop doubler. The IFOG device includes a light source, a circulator in optical communication with the light source and a photo diode, an integrated optical chip (IOC) capable of splitting light emitted from the circulator into two paths each of which is capable of being modulated, the IOC further being capable of combining light from each of the two paths when light travels in a direction towards the circulator, a fiber coil, and a polarization maintaining (PM) combiner / splitter disposed in between the IOC and the fiber coil. The PM combiner / splitter operates to send light through the fiber coil a first time in a first polarization state and to subsequently send the same light a second time through the fiber coil in a second orthogonal polarization state, whereby light travels twice the distance compared to a single loop IFOG device and, as such, effectively doubles the LD product.

The present invention belongs to the field of optical fiber laser technology, and features that the full optical fiber multi-wavelength Raman laser with flat broadband envelope consists of high nonlinearity Raman gain fiber, two wideband WDM couplers connected on two sides of the Raman gain fiber separately, zero-dispersion high nonlinearity fiber, comb filter, wideband fiber loop reflectors on two ends and fibers to constitute laser transmission channel. The full optical fiber multi-wavelength Raman laser may have increased optical coupler and wideband fiber coupler to constitute single-way circulating fiber ring cavity. Compared with conventional optical fiber multi-wavelength Raman laser, the present invention has the advantages of utilizing pump source with small wavelength number in obtaining flat broadband envelope and flexible waveband design of the output laser spectrum.

The invention provides a double reference length low coherent optical fiber ring network sense demodulating equipment, comprising a wide spectrum optical source, a photo detector, an optical fiber 4*4 coupler, a self-focusing lens, a pyramid plane reflector groups, a monomode fiber, an optical fiber ring network composed a plurality of optical fiber sensors with different lengths in series; the wide spectrum optical source and the photo detector are connected with the two optical fiber input ends of the optical fiber 4*4 coupler, and the other two optical fiber input ends of which are respectively connected with the self-focusing lens, which the two optical fiber output ends of the optical fiber 4*4 couple are connected with the optical fiber ring network through the monomode fiber, and the other two optical fiber output ends of which are respectively connected with the self-focusing lens. According to the invention, through the durable optical fiber ring chamber of the double reference optical path, the expansion of the optical path scanning range can be realized, and the multiplexing number of the sensors is added, which has simple structure, easy implement, high accuracy of measurement and low cost and the like.

An apparatus for detection and measurement of trace species in a gas or liquid sample. A ring down cell formed from a fiber optic ring is exposed to the sample gas or liquid. A coherent source emits radiation into the fiber optic ring, which in turn is received at an output thereof. The fiber optic ring has a portion thereof, between the input and output, exposed to the sample gas or sample liquid. A processor is coupled to the receiver and determines the level of trace species in the gas or liquid sample based on the rate of decay of the radiation within the fiber optic ring.

The invention discloses a variable groove width skeleton tool and a method for forming fiber rings by utilizing the tool. The method comprises the following steps of designing a groove-width-adjustable dismountable winding skeleton tool, wherein the groove width can be adjusted to meet the requirements of winding in any integral number of turns according to different diameters of fibers; winding photonic crystal fibers on the dismountable skeleton by using a special winding technology and a low-tension winding technology; curing the photonic crystal fibers to improve the performance level of photonic crystal fiber rings by using a novel gluing curing technology; dismounting the dismountable skeleton tool to obtain formed photonic crystal fiber rings. According to the skeleton tool and the method, a gluing curing process is a glue impregnation curing process, and new adhesive curing conditions, a novel curing adhesive, a novel gluing curing process and stress releasing measures are designed, so that the residual curing stress of the photonic crystal fiber rings and changes in the inner void structure of the photonic crystal fibers are reduced, and the environmental characteristics of the photonic crystal fiber rings are improved.

The invention relates to an interference optical fiber gyroscope which comprises a wide-spectrum light source, a light source end coupler, a depolarizer on the front portion of a ring, a coupler at the end of the ring, a single-mode fiber ring and a photoelectric detector. The output end of the wide-spectrum light source is coupled with a first port of the light source end coupler through single-mode fiber, a third port of the light source end coupler is coupled with one end of the depolarizer on the front portion of the ring through the single-mode fiber, the other end of the depolarizer on the front portion of the ring is coupled with a first port of the coupler at the end of the ring through the single-mode fiber, a third port and a fourth port of the coupler at the end of the ring are coupled with two ports of the single-mode fiber ring through the single-mode fiber respectively, and a second port of the light source end coupler is coupled with the input end of a photoelectric detector through the single-mode fiber. The gyroscope structure omits a polarizer in a minimum reciprocity structure of a gyroscope, non-reciprocal errors are removed through decoherence and interference light intensity compensation between two polarization states, cost is greatly reduced, simultaneously noise is low, and bias stability is good.

The invention discloses a nonlinear polarization rotary mode-locked and wavelength tunable type L-waveband femtosecond Er-doped fiber laser and belongs to wavelength tunable type femtosecond pulse lasers. The nonlinear polarization rotary mode-locked and wavelength tunable type L-waveband femtosecond Er-doped fiber laser comprises a pumping source and an optical fiber ring cavity, wherein the optical fiber ring cavity is formed by connecting a wavelength division multiplexer, Er-doped fibers, an optical fiber isolator, an optical fiber polarizer, an optical fiber coupler and optical fibers used in a polarization controller, the pumping source is connected with the pumping port of the wavelength division multiplexer, a public port of the wavelength division multiplexer is connected to the 80% output port of the optical fiber coupler after passing through the Er-doped fibers, the optical fiber isolator and the optical fiber polarizer in sequence, and the input end of the optical fiber coupler is connected to a signal port of the wavelength division multiplexer through the polarization controller; the optical fiber isolator is connected with the optical fiber polarizer through dispersion compensation fibers, and the other devices are connected through single-mode optical fibers. The nonlinear polarization rotary mode-locked and wavelength tunable type L-waveband femtosecond Er-doped fiber laser has the advantages that the structure is simple and reliable, maintenance is convenient, external signal modulation is not needed, self-starting mode locking can be achieved, output pulses are narrow, the working performance is excellent, cost is low, and operation is easy.

The invention discloses a distributed fiber disturbance sensor based on a Sagnac interferometer. A Sagnac interferometer is used for coupling an arm, synchronously a delayed fiber ring is added, namely a delayed fiber ring is superposed in a single Sagnac interferometer to form two Sagnac interferometers with different length; the time division multiplexing of the two Sagnac interferometers with different length is realized by the propagation of optical pulses in the interferometer; and the positions of disturbing points are calculated to realize the distributed sensing of the disturbance according to the amplitude of output signals of two Sagnac interferometers. The sensor has the advantages of low cost, simple structure and good stability.

The invention relates to a distributed optical fiber temperature sensor calibration and correction constant temperature device and belongs to the optical fiber temperature measurement technical field. The distributed optical fiber temperature sensor calibration and correction constant temperature device is characterized in that the mechanical structure part of the device is composed of an optic fiber ring, a high-precision temperature sensor probe, middle heat conduction silica gel, a left semiconductor refrigeration sheet, a right semiconductor refrigeration sheet, left conduction silica gel, right conduction silica gel, a left heat dissipation sheet, a right heat dissipation sheet, a left heat dissipation fan and a right heat dissipation fan. The distributed optical fiber temperature sensor calibration and correction optic fiber ring is embedded into the designed mechanical structure, so that the modular calibration and correction constant temperature device can be formed. The calibration and correction constant temperature device has the advantages of quick temperature response and high stable temperature precision as well as high reliability, compact structure, convenient installation and the like in conditions having strict requirements for distributed optical fiber temperature sensor calibration and correction.

The invention discloses a millimeter wave generating device based on an optic-fiber ring resonator and a method thereof. The optic-fiber ring resonator is formed by connecting a semiconductor optical amplifier, a 1*2 polarization maintaining coupler, a Mach-Zehnder intensity modulator, a three-port polarization maintaining circulator, a polarization maintaining fiber grating and a polarization maintaining optical delay line in sequence, the output of the optic-fiber ring resonator obtained through the other output end of the 1*2 polarization maintaining coupler is connected with a high-speed photoelectric detector through an optical comb filter with an adjustable wavelength, and when the Mach-Zehnder intensity modulator modulates a microwave source with the frequency being fm, and millimeter wave signals with the being 4fm are generated at the radio-frequency output end of the high-speed photoelectric detector through controlling the DC offset voltage of the Mach-Zehnder intensity modulator and the length of the fine-tuning polarization maintaining optical delay line. The invention has the advantages of high millimeter-wave efficiency, compact structure, stable operation, electromagnetic interference resistance and the like.