266 results about "Optical circulator" patented technology

The invention relates to a phase-sensitive optical time domain reflectometer based on multi-frequency reference switching. Continuous laser generated by a continuous laser is divided into a local path and a detection path through an optical coupler; the local path is input to the polarization coherent receiving module, the detection path is incident to a light intensity modulator driven by the signal generation circuit module, and the light intensity modulator is converted into a multi-frequency pulse laser sequence with intensity modulation; the multi-frequency pulse laser sequence enters the sensing optical fiber to be measured through the optical circulator; generated Rayleigh backscattered light and local continuous laser are subjected to beat frequency coherent receiving in a polarization coherent receiving module through a circulator; and the signal acquisition circuit adopts a demodulation algorithm to compensate phase drift and sensitivity difference of detection pulse demodulation signals with different frequencies so as to realize dynamic strain sensing. Compared with the prior art, the phase drift and the sensitivity difference between the frequencies are extracted to realize the compensation of the interleaved signals, and the method does not depend on the fixed reference frequency, so that the robustness and the adaptability of the system in a complex environment are remarkably enhanced.

The present invention provides a non-contact optical fiber sensing system and method. The system includes a passive fiber Bragg grating sensor and an active demodulation analyzer. The passive fiber Bragg grating sensor includes an optical fiber and a fiber Bragg grating sensor connected in series on the optical fiber. The active demodulation analyzer includes a laser light source, an optical circulator, and a demodulation analyzer. One end of the passive fiber Bragg grating sensor is connected with a first fiber collimator. The active demodulation analyzer further includes a second fiber collimator and an alignment mechanism. The laser light source is connected to the first end of the optical circulator for outputting an optical signal. The optical fiber led out from the second end of the optical circulator is connected with the second fiber collimator. The second fiber collimator is used for non-contact alignment with the first fiber collimator under the adjustment of the alignment mechanism so as to transmit the optical signal bidirectionally. The demodulation analyzer is connected to the third end of the optical circulator. The present invention can expand the application scenarios of the optical fiber sensing system and save costs.

According to the distributed fiber grating sensor provided by the invention, the optical pulse and the broadband laser are emitted in a time-sharing manner through the integrated composite light source module, and the cooperative monitoring of Raman scattering temperature measurement and Bragg grating stress measurement is realized on the same sensing optical fiber in combination with the optical path design of the wavelength division multiplexer and the optical circulator. According to the scheme, the high-temperature adaptability of the Raman scattering effect, namely a stable linear relation between molecular vibration frequency shift and temperature, is utilized, signals and stress are completely decoupled, the problem of cross sensitivity of a traditional single sensor is avoided, and independent measurement can be achieved without temperature compensation; meanwhile, a distributed measurement mode enables the sensor to still perform high-precision synchronous monitoring on temperature and stress in a high-temperature environment of 600-900 DEG C, so that the measurement process in an industrial complex scene is simplified, and the system reliability is improved.

This invention relates to a Bragg light generation system and method suitable for Bragg-type atomic interferometers. The system includes: a laser for generating a first laser beam with a frequency in a preset atomic absorption peak band; an optical circulator for propagating the first laser beam to a cascaded acousto-optic modulator and receiving two third laser beams returned from the cascaded acousto-optic modulator; a cascaded acousto-optic modulator for diffracting the first laser beam into two second laser beams with opposite propagation directions through Bragg diffraction of two acousto-optic crystals; an optical assembly for performing secondary diffraction on the two second laser beams and reflecting the two mutually perpendicular second laser beams to the cascaded acousto-optic modulator; and an output module for splitting and sampling the two third laser beams and modulating the sampled third laser beams into Bragg laser beams in the target frequency band. This invention reduces the path separation of the two Bragg laser beams by using a quasi-common optical path, thereby reducing phase noise and improving measurement accuracy.

The application discloses a kind of EFPI optical fiber sensor multi-sensor multiplexing temperature-pressure demodulation system and method, including ASE broadband laser, optical circulator, EFPI optical fiber sensor, 2-way wavelength division multiplexer, N-way wavelength division multiplexer, N-way wavelength division demultiplexer, photoelectric detector, FBG, 1*2 optical fiber coupler, optical spectrometer, data processing system;The input port input of the optical circulator is connected with ASE broadband laser, the output port cir2 is connected with two cascaded FBGs, the output port cir3 is connected with EFPI optical fiber sensor, the input port of 2-way wavelength division multiplexer is connected with the output port cir4 of optical circulator, and the output port is connected with N-way wavelength division multiplexer;N-way wavelength division multiplexer is accessed via the input port of 1*2 optical fiber coupler, and outputs two-way signals, one-way is connected with N-way wavelength division demultiplexer via N-way photoelectric detector and data processing system, and the other way is connected with optical spectrometer;N channels are connected by cascaded FBG, and the cascade of N EFPI optical fiber sensors is realized.

The invention belongs to the technical field of optical gas sensing, and provides an optical fiber microcavity gas sensing system and method based on photoacoustic excitation and detection enhancement. The sensing system comprises a narrow linewidth laser light source, a wide-spectrum detection light source, a wavelength division multiplexer, an optical circulator, a high-speed spectrometer, a signal processing circuit, a single-mode optical fiber and an embedded single-optical-fiber photoacoustic sensing probe. The novel structure is characterized in that the partially gold-plated optical fiber is embedded into the gold-plated opto-acoustic micro-cavity to form a miniature optical'cage ', so that multiple reflections of light in a free space are realized. In addition, in order to make full use of the high sensitivity of the silicon cantilever beam in photoacoustic detection, the structural design of the embedded single optical fiber for expanding the inner cavity reduces the pressed film damping of the silicon cantilever beam during resonance. According to the embedded single-optical-fiber photoacoustic sensor, the multi-pass photoacoustic microcavity and the ultra-sensitive optical fiber microphone are applied, so that double enhancement of photoacoustic excitation and detection is realized, and the gas detection precision is improved.

The invention discloses a distributed optical fiber two-dimensional vector sensing system and method, the system uses an acousto-optic modulator group and an optical circulator group to ask a plurality of fiber cores of a multi-core optical fiber in parallel, heterodyne coherent detection uses local oscillator light to improve the signal-to-noise ratio, and through the relation between the fiber core position difference and the direction angle of a two-dimensional sound wave in the aspect of algorithm, the two-dimensional sound wave direction angle is obtained. According to the space division multiplexing distributed optical fiber acoustic sensing system, a two-dimensional vector signal is accurately restored, the measurement vector angle range of the space division multiplexing distributed optical fiber acoustic sensing system for two-dimensional sound waves is 0-360 degrees, the vector sensing range is larger than 50 km and far exceeds that of an existing system, and the detection capacity of the distributed optical fiber acoustic sensing system is greatly improved.

The invention relates to the technical field of optical fibers, and provides a device and method for measuring size structure parameters of a hollow-core optical fiber, and the device comprises a light source transmitting end (11), an optical circulator (12), a spectrometer (13), and a rotary displacement platform (14). The light source emitting end (11) is connected with a first port (1) of the optical circulator (12), a second port (2) of the optical circulator (12) is aligned with the side surface of a to-be-detected hollow-core optical fiber (15) of which a coating layer is stripped, the to-be-detected hollow-core optical fiber (15) of which the coating layer is stripped is arranged in the rotary displacement table (14), and a third port (3) of the optical circulator (12) is connected with the spectrograph (13); the to-be-tested hollow-core optical fiber (15) is a band-gap hollow-core optical fiber or an N-layer nested anti-resonance hollow-core optical fiber, and N is a positive integer; the detection device is simple in composition, and the detection method is convenient to operate, simple in calculation and good in measurement accuracy.

The invention relates to a Bragg light generation system and method suitable for a Bragg atom interferometer, and the system comprises a laser device which is used for generating first laser with the frequency on a preset atomic absorption peak frequency band; the optical circulator is used for transmitting the first laser to the cascade acousto-optic modulator and receiving two beams of third laser returned by the cascade acousto-optic modulator; the cascade acousto-optic modulator is used for diffracting the first laser into two beams of second laser with opposite propagation directions through Bragg diffraction of the two acousto-optic crystals; the optical assembly is used for carrying out secondary diffraction on the two beams of second laser and reflecting the two beams of second laser which are obtained through diffraction and are perpendicular to each other to the cascade acousto-optic modulator; and the output module is used for carrying out light splitting sampling on the two beams of third laser and modulating the sampled third laser into Bragg laser of a target frequency band. According to the invention, path separation of the two Bragg laser beams is reduced through quasi-common-path, so that phase noise is reduced, and measurement precision is improved.

The invention discloses an on-chip fully-integrated optical circulator based on phase modulation. The on-chip fully-integrated optical circulator comprises a substrate, a buried oxide layer, an optical waveguide layer, an upper cladding and a metal layer used for manufacturing metal electrodes, the substrate, the buried oxide layer, the optical waveguide layer, the upper cladding and the metal layer are stacked, the optical waveguide layer comprises two input / output optical waveguide groups, a four-port resonant cavity and two metal electrode pairs, and the metal layer comprises four modulation areas; four ports of the resonant cavity are respectively connected with four interfaces of the modulation area, each input / output optical waveguide group is connected by a bent optical waveguide and coupled to the resonant cavity, the middle of the metal electrode pair is bent to form a coplanar waveguide electrode, and the middle of each two ends of the modulation area is connected by the coplanar waveguide electrode. The fully-integrated optical circulator is realized under the silicon-based substrate for the first time, is compatible with current mainstream optical integration platforms such as SOI, LNOI and LTOI, and can be widely applied to large-scale photonic integrated chips, such as the fields of optical communication, optical sensing, on-chip optical interconnection and the like.

The invention discloses single-photon non-destructive measurement equipment based on a micro-ring resonant cavity, and the equipment comprises a signal light input waveguide, a signal light output waveguide, a detection light input waveguide, a detection light output waveguide, a first optical circulator, a second optical circulator, a linear waveguide, the micro-ring resonant cavity, and a three-level quantum emitter. The first ends of the signal light input waveguide, the probe light output waveguide and the linear waveguide are respectively connected to the first optical circulator, the second ends of the signal light output waveguide, the probe light input waveguide and the linear waveguide are respectively connected to the second optical circulator, and the micro-ring resonant cavity is coupled with the linear waveguide. And the three-level quantum emitter is coupled with the micro-ring resonant cavity. The method is high in measurement efficiency and high in measurement precision.

A lidar system, including: a laser, an optical detector, a laser antenna, and a silicon-based integrated magneto-optical circulator. The silicon-based integrated magneto-optical circulator includes a silicon-based integrated Mach-Zehnder interference structure or a silicon-based integrated micro-ring structure, and silicon-based integrated magneto-optical waveguides. The silicon-based integrated magneto-optical circulator further includes an input port, a receiving port, and an emission port. The laser is aligned and coupled to the input port of the silicon-based integrated magneto-optical circulator via an optical fiber, a grating coupler, or an edge coupler. The optical detector is aligned and coupled to the receiving port of the silicon-based integrated magneto-optical circulator via the optical fiber, the grating coupler, or the edge coupler. The laser antenna is aligned and coupled to the emission port of the silicon-based integrated magneto-optical circulator via the optical fiber, the grating coupler, or the edge coupler.

The present invention relates to an optical fiber acoustic sensor with improved acoustic signal measurement sensitivity, and includes: a light source unit that generates and outputs pulsed light; an optical circulator that outputs the pulsed light output from the light source unit and input to an input terminal through an output terminal, and outputs light incident reversely from the output terminal through a detection terminal; a sensing optical fiber connected to the output terminal of the optical circulator and installed to extend over a measurement target region; at least one acoustic focusing member having the sensing optical fiber wound thereon multiple times, arranged in a measurement target region and adapted to focus an external acoustic signal; a light detection unit that detects Rayleigh scattered light scattered in the sensing optical fiber and traveling reversely; and a signal processing unit that control generation of the pulsed light by the light source unit and measures a vibration frequency and an intensity of acoustic received through the sensing optical fiber from a signal detected by the light detection unit, based on an output time point of the pulsed light.

An optical circulator includes a first polarization beam splitter member having a common optical port, a second polarization beam splitter member having an emittance optical port and at least two receiving optical ports, and a first polarization adjustment member. The two receiving optical ports respectively receive two linearly polarized light beams. The two linearly polarized light beams respectively pass through the second polarization beam splitter member, and sequentially pass through the first polarization adjustment member and the first polarization beam splitter member to be combined into a first combined light beam for being output from the common optical port. The common optical port receives a compound optical signal that passes through the first polarization beam splitter member to be split into another two linearly polarized light beams that are combined into a second combined light beam for being output.

The application discloses a Stokes parameter encoder, which comprises a fiber optical circulator and an optical path round trip path; a polarization maintaining fiber Faraday rotator is arranged on the optical path round trip path to rotate the polarization of light by 45 degrees; the fiber optical circulator is a polarization maintaining fiber optical circulator; the fiber optical polarization beam splitter is a polarization maintaining fiber optical polarization beam splitter; the delay fiber is a polarization maintaining delay fiber; and the fiber optical phase modulator is a polarization maintaining fiber optical phase modulator. The application further discloses a parameter encoding method of the encoder. The above technical scheme can perfectly offset the rotation angle deviation problem caused by the device, can guarantee the stability of the rotation angle regardless of the angle deviation of the device, is easy to realize the driving circuit, is easy to integrate and small in size due to the pure fiber structure, and can realize the continuous variable quantum key distribution of the complete GG02 protocol based on the Stokes encoder.

The invention discloses an all-fiber three-dimensional tomography system, which is used for performing three-dimensional tomography on an object to be observed at a high speed and comprises a light source, a first optical coupler, a first optical circulator, a first optical collimator, a first convex lens, an electric control attenuator, a second optical circulator, a second optical collimator, a second convex lens, a second optical coupler and a balance detector. The light source included in the all-fiber three-dimensional tomography system can quickly perform line or plane scanning on optical scattering media such as biological tissues and the like by utilizing a technology of capturing optical signals to obtain images and adopting an all-fiber line architecture, so as to obtain high-resolution three-dimensional images.

The application provides a semiconductor laser reservoir pool computing device based on silicon-based micro-resonant cavity optical feedback, and belongs to the technical field of photonic neuromorphic computing. Laser output by a driving laser is modulated by a phase modulator, and then is injected into a response semiconductor laser through a feedback cavity incoupler and a circulator; the output end of the response semiconductor laser is connected to an optical circulator in sequence through a second variable optical attenuator, a polarization controller, a silicon-based micro-resonator and a first variable optical attenuator, so as to form a silicon-based micro-resonator optical feedback loop; the output end of the feedback cavity incoupler is connected to a broadband photodetector, which is used to collect reservoir pool output signals; the phase modulator is loaded with a modulation signal containing an input signal and a random mask, so as to realize input layer signal coding. The application realizes the improvement of overall computing performance.

The application provides a polarization-dependent reflective two-stage optical ring, which comprises a first collimator, a first beam splitting cube, a first optical rotation component, a second beam splitting cube, a third beam splitting cube of a second optical rotation component and a second collimator arranged along a first optical path, and three beam splitting cubes are respectively light splitting dielectric films; the application combines the characteristics of a transmission two-stage ring and a reflective ring, two optical rotation components are arranged on the first optical path from the first collimator to the second collimator, thereby realizing the series connection of two isolation systems, playing a double-stage isolation effect, meanwhile, the application realizes the optical path folding of a second optical path from the second collimator to the third collimator by using a reflective component, and optical components are multiplexed in one of the optical rotation components, thereby also achieving a double-stage isolation effect; while realizing the double-stage isolation effect, the application also reduces the product volume, is beneficial to the integration of equipment and is also beneficial to cost reduction.

The present disclosure describes a single aperture laser range finder (SALRF). In an implementation, the single aperture laser range finder includes a beam extender including an aperture and an input aperture lens. A matching lens collimates light emitted from an emitter element associated with a single aperture optical circulator and received by the beam extender, respectively. A single aperture optical circulator has an emitter channel associated with the emitter element and a detector channel associated with a detector element. The emitter channel and the detector channel merge together at an input / output aperture. A light gating mechanism is configured to permit received light to enter the detector channel and to prevent the received light from entering the emitter channel. The SALRF has an electronics end cap.

The utility model is suitable for the technical field of optical equipment, and provides a Faraday rotator, an optical isolator and an optical circulator. The Faraday rotator comprises a magneto-optical component and a magnetic field applying piece, and the magnetic field applying piece can apply an external magnetic field to the magneto-optical component; the magneto-optical component can enable the polarization state of the polarized light to rotate by a preset angle along a first turning direction in an external magnetic field, and the preset angle forms an optical rotation angle; the magneto-optical component is provided with a light incident surface and a reflecting surface which are oppositely arranged, a first light-transmitting film and a second light-transmitting film are sequentially arranged on the light incident surface, and a first reflecting film is arranged on the reflecting surface; when one of the first light-transmitting film and the second light-transmitting film passes through the polarized light propagating toward the first reflective film, the other passes through the polarized light and emits the polarized light to the outside of the magneto-optical member. By means of the design, the Faraday rotator can still achieve the original effect on the premise that the size of the magnetic field generating piece is reduced, and reduction of the overall size of the Faraday rotator is facilitated.

The application discloses a microwave photon filter and a control method thereof, and belongs to the field of optical fiber communication. The filter comprises an optical ring cavity, a tunable laser source, an electro-optic intensity modulator, a photoelectric detector and an electric vector network analyzer. The first input end of the electro-optic intensity modulator is connected with the output end of the tunable laser source, the second input port of the electro-optic intensity modulator is connected with the output end of the electric vector network analyzer, and the output end of the electro-optic intensity modulator is connected with the input end of an optical circulator in the optical ring cavity. The output end of the optical circulator in the optical ring cavity is connected with the input end of the photoelectric detector, and the output end of the photoelectric detector is connected with the input end of the electric vector network analyzer. The application can overcome the problem that the device parameters cannot be adjusted after the structure of the microwave photon filter is determined.

The application belongs to the technical field of optical fiber preparation automation, and specifically discloses a femtosecond laser-based optical fiber grating automatic processing and sorting system and method. The system comprises a sorting unit, a processing unit and a detection unit. The sorting unit comprises a feeder for automatically feeding optical fibers during processing, a winding machine connected with the feeder through an optical fiber and used for packaging and winding the finished optical fibers, and an industrial robot used for sorting the packaged finished optical fibers. The processing unit is arranged between the feeder and the winding machine and is used for processing optical fiber gratings. The detection unit comprises a test light source, an optical circulator, an optical spectrum analyzer and a loss module. The optical circulator is connected with the test light source, the optical spectrum analyzer and the optical fiber on the feeder. The loss module is arranged between the processing unit and the winding machine and blocks the propagation of test laser emitted by the test light source in the optical fiber through a bent optical fiber. The control unit is in communication connection with the processing unit, the sorting unit and the detection unit and is used for realizing optical fiber grating automatic processing and sorting.

The invention discloses an active mode demultiplexing module which comprises a mode converter, two optical circulators and a bidirectional semiconductor optical amplifier. The mode converter is used for converting a high-order mode into a fundamental mode to complete primary mode demultiplexing, fundamental mode signals after primary demultiplexing are injected into the bidirectional semiconductor optical amplifier through the two optical circulators from the positive direction and the negative direction respectively, and the signals after being shaped by the bidirectional semiconductor optical amplifier are output by the corresponding optical circulators. A bidirectional symmetrical injection structure is formed, different propagation is beneficial to separation of different signals, and mutual interference, namely mode crosstalk, between forward and reverse signals can be effectively reduced, so that a mode demultiplexing function is better completed, and an output signal has higher signal quality than a primary demultiplexing signal. Besides, by optimizing and adjusting the driving current of the bidirectional semiconductor optical amplifier or an auxiliary optical pumping mode, not only can the gain of the mode channel be dynamically adjusted, but also the power balance of the mode channel and the demultiplexing of a high extinction ratio mode can be realized; the method is especially suitable for receiving few-mode signals in a mode division multiplexing (MDM) optical transmission system and constructing optical switching nodes in a multi-dimensional multiplexing optical network.

The present invention relates to the field of distributed optical fiber sensing, and discloses a chaotic Brillouin optical frequency domain - correlation domain fusion reflection sensing device and method. In the device, the phase - type chaotic laser output by a phase - type chaotic laser source is divided into two beams by a beam splitter. One beam serves as the signal light and is incident on a sensing optical fiber after passing through a modulator and an optical circulator in sequence. The generated chaotic backward Brillouin scattered light enters a combiner through the optical circulator. The other beam serves as the reference light and enters the combiner through a programmable optical delay generator to produce a beat - frequency effect with the chaotic backward Brillouin scattered light. The generated Brillouin beat - frequency signal is collected by a broadband photodetector. The signal output end of the broadband photodetector is connected to the first signal input end of a mixer. The second signal input end of the mixer is connected to a radio - frequency signal. The signal output end is connected to a vector network analyzer through a low - pass filter. The present invention can achieve high - precision positioning, high spatial resolution, and high - precision measurement.

To provide an optical transmission device, an optical transmission system, and an optical transmission method that suppress an OSNR penalty due to return light.SOLUTION: An optical transmission device disposed at a fiber end of a single-core optical fiber and used when signal light is bidirectionally transmitted through the optical fiber, the optical transmission device comprising an optical transmitter configured to transmit first signal light in one direction belonging to the signal light, an optical receiver configured to receive second signal light in a reverse direction belonging to the signal light, and a controller configured to guide the first signal light transmitted from the optical transmitter to the optical fiber, An optical circulator configured to guide the second signal light from the optical fiber to the optical receiver; and a light source configured to output, to the optical fiber, excitation light that Raman-amplifies the second signal light to second optical power higher than first optical power of the first signal light.SELECTED DRAWING: Figure 2

A temperature strain separable dynamic and static combined measurement distributed optical fiber sensing system, comprising: laser, optical modulator, radio frequency signal generator, optical filter, DFB laser, polarization controller, first acoustooptic modulator, depolarizer, erbium-doped fiber amplifier, two optical circulators, optical wavelength division multiplexer, receiving module, signal acquisition and processing module are arranged in sequence, the application carries out temperature sensing to the back Raman scattering light of the pulse while receiving the Rayleigh scattering light of the detection pulse, and controls the time interval of adjacent pump pulse and detection pulse to carry out three-bit pulse coding and decoding, so that the back Raman scattering signals of individual pulse in pulse pair are separated in time, and finally the simultaneous measurement of dynamic variable (vibration) and static variable (temperature, static strain) is realized and the spatial resolution of measurement is ensured not to be lost.

The invention discloses a microwave photon long-distance transmission link phase automatic compensation method and device, and the method comprises the steps: a modulation signal is loaded on an optical carrier signal outputted by a laser through a cascade modulator, and an optical frequency comb signal outputted by the cascade modulator is divided into two paths after passing through an optical coupler, wherein one path is input into the optical circulator through the first optical filter and is forwards transmitted to the optical reflection module through one path of optical fiber, the optical reflection module reflects back transmitted optical signals, the optical signals are input into the optical circulator and then are output to the first optical detector through the other port of the optical circulator, and radio-frequency signals are output after photoelectric conversion; the other path of optical signal output by the optical coupler is input into the optical modulator through a second optical filter to serve as a carrier signal, and a radio frequency signal is loaded on the optical modulator, is forwards transmitted through another path of optical fiber and is output to a second optical detector through a third optical filter; the method has the advantages of high response speed, system order establishment and large compensation range.