27 results about "Microwave photonic filter" patented technology

The invention discloses a reconfigurable microwave photonic filter, which comprises a laser source, an electro-optical modulator, an adjustable feedback type array waveguide grating, a filtering module and a photoelectric detector, and is characterized in that the laser source generates an optical signal and transmits the optical signal to the electro-optical modulator, and the electro-optical modulator modulates the optical signal after receiving the optical signal to form a corresponding sideband; the adjustable feedback type array waveguide grating divides the frequency spectrum of an optical signal into different wavelengths and carries out independent amplitude and phase adjustment on the optical signal with different wavelengths, then the filtering module filters out periodically repeated signals, and the photoelectric detector converts the filtered optical signal into an electric signal, so that optical-electric conversion is completed. The reconfigurable microwave photonic filter and the filtering method have the advantages of being simple in structure, highly programmable in frequency spectrum shape, rapid and reconfigurable in response and high in integration level, and have great attraction to the field of high-frequency signal processing. The application obtains the Young Science Foundation project (62204156) of the National Natural Science Foundation.

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 discloses a reconfigurable microwave photonic filter, comprising a laser source, an electro-optic modulator, an adjustable feedback type array waveguide grating, a filtering module and a photoelectric detector, the laser source generates an optical signal which is transmitted to the electro-optic modulator, the electro-optic modulator modulates the optical signal after receiving the optical signal, forms a corresponding sideband, the adjustable feedback type array waveguide grating divides the spectrum of the optical signal into different wavelengths, and independently adjusts the amplitude and phase of the optical signals with different wavelengths, then the filtering module filters out the periodically repeated signals, and the photoelectric detector converts the filtered optical signal into an electrical signal, thereby completing the optical-electric conversion. The reconfigurable microwave photonic filter and the filtering method have the advantages of simple structure, highly programmable spectrum shape, fast reconfigurable response and high integration, and will have great attraction in the field of high-frequency signal processing. The application obtains: National Natural Science Foundation of China Youth Science Foundation Project (62204156).

The invention discloses an ultra-wideband weak signal detection method and system based on all-optical oscillation and phase-amplitude conversion. The method comprises the steps that spontaneous radiation light generated by an erbium-doped optical fiber amplifier is used as an optical carrier; modulating a weak radio frequency signal to be measured received by an antenna to the optical carrier through an optical modulator to form a modulated optical signal; the modulated optical signal is injected into an all-optical oscillation circuit composed of double loops, the all-optical oscillation circuit generates multimode optical oscillation by adjusting an optical attenuator, and the all-optical oscillation circuit comprises a double-loop interference structure; performing phase-amplitude conversion by adjusting the delay difference of the two light paths in the double loops to form an equivalent microwave photon filter so as to select and amplify the modulated light signal corresponding to the radio frequency signal of the set frequency band; and converting the selected and amplified modulated optical signal into an electric signal, and performing spectral analysis to detect the weak radio frequency signal to be detected.

This invention relates to the fields of optical fiber communication and microwave photonics. Existing tunable dual-passband microwave photonic filters suffer from poor passband stability and cannot meet practical application requirements. This invention provides a narrow-band tunable dual-passband microwave photonic filter using a Brillouin fiber laser. It generates dual-tone pump light to excite the Brillouin using a tunable laser source and an intensity modulator. Combined with a Brillouin fiber oscillator and a cascaded Fabry-Perot cavity, the Brillouin gain spectrum is narrowed to the kHz level. Simultaneously, the different periodic resonant frequencies of the two ring cavities effectively suppress side modes, filtering out the desired frequency band signal. Furthermore, by synchronously tuning the center frequencies of the two passbands of the filter by changing the pump light wavelength, and simultaneously controlling the output frequency of the signal generator, the frequency interval between the two passbands is changed, ultimately realizing a narrow-linewidth tunable dual-passband microwave photonic filter.

A diaphragm-type optical fiber micro-vibration measurement apparatus and method based on a single-pass band microwave photonic filter. The apparatus comprises a broadband light source module (1), a three-port circulator (2), an AU diaphragm optical fiber micro-vibration sensor (3), an erbium-doped optical fiber amplifier (4), a polarization controller (5), an electro-optical modulator (6), a power supply module (7), a radio-frequency source module (8), a dispersion compensation optical fiber (9), a photoelectric detector (10), a data acquisition card (11) and a computer (12), wherein the broadband light source module (1) is connected to one port of the three-port circulator (2) by means of an optical fiber connection line.

The invention belongs to the field of optical fiber signal spectrum parameter testing, and relates to an ultra-wideband light generation device and method based on a microwave photonic filter. The device comprises a main control unit, and a broadband light generation unit and an active tuning narrowband filtering unit which are connected with the main control unit, the broadband light generation unit and the active tuning narrowband filtering unit are connected through an optical isolator. The main control unit comprises an embedded system and is configured to be used for controlling the ultra-wideband light generation process and setting working parameters; the broadband light generation unit is configured to be used for generating an ultra-broadband light signal; the active tuning narrowband filtering unit is configured to be used for performing ultra-narrowband active tuning filtering on the ultra-wideband optical signal generated by the wideband optical generation unit, and generating frequency sweeping light capable of performing frequency domain scanning with a configurable ultra-narrow bandwidth in an ultra-wideband range; the generation of signal light with active tunable ultra-narrow sweep frequency bandwidth and ultra-wide frequency band range is realized.

The invention discloses an all-optical integration system, comprising: an optical envelope to be integrated is connected to the input end of a first-stage two-tap positive coefficient microwave photon filter (1); the output end of the first-stage two-tap positive coefficient microwave photon filter (1) is connected to the first input end (9a) of a three-port optical circulator; the output end of a laser source (6) is connected to the input end of an optical isolator (7); the output end of the optical isolator (7) is connected to the input end of an optical envelope detection module (8); the output end of the optical envelope detection module (8) is connected to the second input end (9b) of the three-port optical circulator; the output end (9c) of the three-port optical circulator is connected to the input end of a second-stage two-tap positive coefficient microwave photon filter (10); and the output end of the second-stage two-tap positive coefficient microwave photon filter (10) is the final output end. The invention avoids complex spectral filtering, has simple devices, and is easy to adjust.

The invention discloses a device and a method for measuring omnidirectional vector bending by using a double-tap microwave photonic filter. According to the device, a multi-core fiber bragg grating is adopted as a bending sensor, a double-tap microwave photonic filter based on a Mach-Zehnder interferometer structure is constructed, and reflected signals of a middle core fiber bragg grating and any one core shift fiber bragg grating are adopted as optical tap signals of the double-tap microwave photonic filter. The wavelength drift of the fiber Bragg grating caused by bending is mapped into the time delay inequality change of the two optical taps, so that the curvature is detected. The measuring device has high measurement resolution and temperature insensitivity, can realize 0-360-degree omnidirectional vector bending measurement, is easy to implement, has a relatively compact structure, has wide application prospects in the fields of structural health monitoring, three-dimensional shape sensing, intelligent robot posture recognition and the like, and is suitable for popularization and application.

The invention discloses a band-pass and band-stop switchable integrated microwave photonic filter based on a film lithium niobate platform. The band-pass and band-stop switchable integrated microwave photonic filter comprises a Mach-Zehnder modulator, a composite structure and a micro-ring resonator, wherein the Mach-Zehnder modulator is integrally manufactured on a film lithium niobate chip; the composite structure is used for adjusting the phase relation between an optical carrier and an optical sideband; according to the invention, the structure is simple, the switching between band-stop filtering and band-pass filtering can be realized through the two micro-ring resonators and the phase shifter, the system complexity is reduced, and flexibility and economical efficiency are realized. According to the invention, the operation is simple, the switching of the filtering function can be realized only by adjusting the voltage of the phase shifter, the dynamic adjustment can be realized according to the actual demand, and the variable application scenarios can be satisfied.

A microwave photon filter with a stable and tunable center frequency belongs to the field of microwave photons. The microwave photon filter includes an optical amplifier, a first optical isolator, a 1×2 optical coupler, an upload-download microring resonant cavity, a first circulator, a microwave source, an electric power divider, a first phase modulator, an intensity modulator, a slave laser, a second circulator, a second phase modulator, a second optical isolator, and a photodetector. The present invention provides a microwave photon filter with a stable and tunable center frequency. It utilizes the complementary characteristics of optical filtering at the transmission end and the download end of the same resonant ring to lock the center angular frequency difference between the optical carrier and the band-stop optical filter in the MPF, so that the angular frequency difference between the optical carrier and the band-stop optical filter is fixed to 2πNf m , thus obtaining the center frequency Nf m The bandpass MPF eliminates the influence of temperature on the center frequency of the MPF and realizes an MPF ​​with a stable center frequency.

The invention discloses a reconfigurable frequency domain mode-locked optoelectronic oscillator capable of generating multiple signal types, and belongs to the field of microwave photons. The reconfigurable frequency domain mode-locked optoelectronic oscillator comprises a waveform generator, a semiconductor laser, an electro-optic phase modulator, a single-mode optical fiber, a dispersion compensation optical fiber, a multi-notch filter integrated chip, a photoelectric detector, an electric amplifier and an electric power divider. Wherein the waveform generator, the semiconductor laser, the electro-optic phase modulator, the single-mode optical fiber, the dispersion compensation optical fiber, the multi-notch filter integrated chip and the photoelectric detector form a reconfigurable microwave photonic filter. According to the invention, the center frequency of each notch in the multi-notch filter integrated chip module is controlled in a thermal tuning manner, and the distance relationship between the center frequencies of different notches is utilized; switching of the reconfigurable frequency domain mode-locked optoelectronic oscillator among three output states, namely a single-chirp LFM signal output state, a double-chirp LFM signal output state and a multi-band LFM signal output state, is realized.

This invention discloses a bandpass / bandstop switchable integrated microwave photonic filter based on a thin-film lithium niobate platform, comprising: a Mach-Zehnder modulator integrated on a thin-film lithium niobate chip, a composite structure for adjusting the phase relationship between the optical carrier and optical sidebands, and a microring resonator for filtering out sidebands. This invention features a simple structure; switching between bandstop and bandpass filtering can be achieved using two microring resonators and a phase shifter, reducing system complexity and offering flexibility and economy. Operation is simple; switching the filtering function only requires adjusting the voltage of the phase shifter, and it can be dynamically adjusted according to actual needs, meeting diverse application scenarios.

The application discloses a band-pass / band-stop dual-output integrated microwave photon filter, which comprises a thin film lithium niobate chip, the thin film lithium niobate chip comprises a first optical waveguide, a first optical coupler, a second optical waveguide and a third optical waveguide, a second optical coupler, a first phase shift waveguide and a second phase shift waveguide, a row wave electrode group, a third optical coupler, a fourth optical waveguide, a first ring resonant cavity, a second ring resonant cavity, a fifth optical waveguide and a fourth optical coupler and a sixth optical waveguide. The application integrates a Mach-Zehnder modulator, a micro-ring resonator, an optical coupler and other basic devices on the thin film lithium niobate chip. The application has a simple structure, and can simultaneously realize complementary band-pass filtering and band-stop filtering through a small number of basic unit devices such as the micro-ring resonator and the optical coupler. The structure except the laser and the detector is integrated on the chip, so that the system power consumption, cost and complexity are reduced, and the system stability is improved.

The invention relates to the technical field of microwave photons, and discloses a flexible channelization device and method based on a reconfigurable microwave photonic filter, and the device comprises a coherent optical comb generation module which is used for generating two sets of coherent optical frequency combs with different repetition frequencies; the radio frequency signal modulation module is used for realizing ultra-wideband radio frequency signal broadcasting of the signal optical frequency comb; the optical domain spectrum elastic bandwidth segmentation module is used for realizing segmentation of signals with different bandwidths in the signal branches; the fine frequency shift module is used for realizing fine frequency shift of the local oscillation optical frequency comb; and the demodulation receiving module is used for realizing demodulation and frequency conversion of the signal light and the local oscillation light of the same channel. According to the invention, elastic bandwidth multi-channel division and flexible frequency conversion receiving processing of broadband signals are realized based on the integrated coherent dual-optical comb source chip and the center frequency and bandwidth reconfigurable microwave photonic filter chip. According to the invention, the flexibility and multifunctional comprehensiveness of the microwave photon channelization system structure are improved.

This invention discloses a wide-tunable single-passband microwave photonic filter and its construction method. The filter includes a light source device for generating a supercontinuum light source, comprising a generator, an RF power amplifier, a DFB laser, a first erbium-doped fiber amplifier, a first variable optical attenuator, and a highly nonlinear fiber connected in sequence. An optical filter for selecting a certain width of supercontinuum light source is connected between the light source device and a MZI structure for spectral segmentation of the supercontinuum light source. The MZI structure is connected to a photodetector via a single-mode fiber and a second erbium-doped fiber amplifier. The photodetector is connected to the MZI structure via a vector network analyzer. This application features a simple structure, low cost, and the constructed complex coefficient filter eliminates the fundamental frequency response.

The present disclosure relates to a narrow-line-width swept photoelectric oscillator and system based on the time-reversal symmetry mechanism, and relates to the field of microwave photonics. The narrow-line-width swept photoelectric oscillator based on the time-reversal symmetry mechanism comprises a microwave photonics filter, a first long optical fiber, a second optical coupler, a gain branch, a loss branch, an electrical combiner, and a second electrical power divider. The output end of the microwave photonics filter is connected with the first long optical fiber and the second optical coupler in sequence. The microwave photonics filter is used to output a first optical signal which is equivalent to an intensity-modulated signal after modulating and filtering an initial optical signal. The first long optical fiber is used to perform delay processing on the first optical signal. The output end of the second optical coupler is connected with the input end of the gain branch and the loss branch, respectively. The gain loop corresponding to the gain branch and the loss loop corresponding to the loss branch satisfy the time-reversal symmetry constraint condition. The output end of the gain branch and the loss branch is connected with the input end of the electrical combiner. The output end of the electrical combiner is connected with the input end of the second electrical power divider. The first output end of the second electrical power divider outputs a narrow-line-width swept signal. The second output end of the second electrical power divider is connected with the input end of the microwave photonics filter, forming a closed loop. The present scheme can improve the quality of the swept signal.

The invention discloses a reconfigurable multi-frequency-point high-precision microwave photonic filter based on a multi-channel narrow-band optical filter chip. Based on a multichannel narrow-band optical filter chip, a laser is introduced as a light source, a phase modulator generates a modulated optical signal, a photoelectric detector converts a filtered optical signal to a radio frequency domain for output, and a vector network analyzer provides the radio frequency signal and performs radio frequency domain analysis on the output signal; the multi-channel narrow-band optical filter chip comprises a cascaded asymmetric Mach-Zehnder interferometer which receives and separates modulated optical signals; the square-wave high-order micro-ring resonator array and the tunable high-Q micro-ring resonator array respectively receive and process the upper sideband optical signal and the lower sideband optical signal; and the coupling module combines the processed upper and lower sideband optical signals, generates a filtered optical signal and outputs the filtered optical signal. According to the multichannel narrow-band optical filter chip provided by the invention, by dynamically regulating and controlling the amplitudes and phases of the optical carrier and the optical sideband, a microwave photonic filter with multi-frequency-point band-pass / band-stop mode switching and continuous tuning of the bandwidth, the extinction ratio and the center frequency is realized.

The invention discloses a microwave photonic filter with stable and tunable center frequency, and belongs to the field of microwave photons. The microwave photonic filter comprises an optical amplifier, a first optical isolator, a 1 * 2 optical coupler, an upload-download type micro-ring resonant cavity, a first circulator, a microwave source, an electric power divider, a first phase modulator, an intensity modulator, a slave laser, a second circulator, a second phase modulator, a second optical isolator and a photoelectric detector. According to the microwave photonic filter with the stable and tunable center frequency provided by the invention, the optical carrier in the MPF and the center angular frequency difference of the band-stop optical filter are locked by utilizing the complementary characteristic of optical filtering at the transmission end and the downloading end of the same resonant ring, so that the angular frequency difference between the optical carrier and the band-stop optical filter is fixed to be 2pi Nfm; therefore, the band-pass MPF with the center frequency being Nfm is obtained, the influence of the temperature on the center frequency of the MPF is eliminated, and the MPF with the stable center frequency is achieved.

This invention discloses a microwave photonic filtering method. The method includes: splitting an optical frequency comb into two paths; performing dispersion compensation on the first optical frequency comb and then splitting it into two local oscillator optical frequency comb signals; using the radio frequency signal to be filtered to perform carrier-suppressed single-sideband modulation on the second optical frequency comb, and performing the same dispersion compensation on the generated modulated optical signal before splitting it into two radio frequency modulated optical frequency comb signals; performing a 90° optical phase shift on one of the local oscillator optical frequency comb signals / radio frequency modulated optical frequency comb signals and coupling it with the other radio frequency modulated optical frequency comb signal / local oscillator optical frequency comb signal, and performing photoelectric detection on the coupled signal to obtain a first electrical signal; coupling the other local oscillator optical frequency comb signal with the other radio frequency modulated optical frequency comb signal and performing photoelectric detection to obtain a second electrical signal; and performing an electrical phase shift on the first electrical signal and then coupling it with the second electrical signal. This invention also discloses a microwave photonic filtering device. Compared with the prior art, this invention can significantly expand the frequency tunable range.

The invention discloses a microwave photon optical fiber interference sensor sensitivity enhancing system. The system comprises a broadband light source, an optical fiber coupler, an optical fiber interference sensor, a narrowband filtering element, an optical fiber amplifier, an electro-optical modulator, a dispersion module, a photoelectric detector and a vector network analyzer which are arranged on the same light path. In order to improve the performance of the optical fiber interference sensor enabled by the microwave photonic filter in precision measurement, coherent microwave superposition is carried out on passband frequency response of the optical fiber interference sensor and flat frequency response of a narrow-band filtering element through an optical fiber coupler, so that trapped waves which are more sensitive to interference spectrum information are generated in a passband; the frequency and the intensity are related to the optical path difference of the optical fiber interference sensor. Through a trap demodulation mechanism based on coherent microwave superposition, the sensing sensitivity of the microwave photon optical fiber interference sensor can be remarkably improved.

The present application relates to narrow bandwidth filter, due to the limited gain bandwidth of erbium-doped fiber, the delay device such as optical fiber affects the period of transfer function in frequency, limited to the Brillouin frequency shift amount of material, the structure of traditional optical fiber ring resonator limits the narrow threshold of stimulated Brillouin scattering gain, the present application provides a kind of switchable Brillouin frequency shift fiber laser high frequency narrow band microwave photon filter, by using the laser generated by switchable Brillouin frequency shift fiber laser and the modulation light coupling, after beating, the narrow bandwidth microwave photon Brillouin filter of narrow bandwidth laser filtering can be realized;Brillouin frequency shift interval selection structure is accessed in switchable Brillouin frequency shift fiber laser, and then the purpose of Brillouin frequency interval selection is achieved.The present application utilizes switchable Brillouin frequency shift fiber laser, the working frequency of narrow linewidth laser output is selected by Brillouin frequency shift interval, and then single passband high frequency narrow bandwidth laser filtering is realized.

The invention provides a microwave photonic filter. The microwave photonic filter comprises an MEMS interferometer, an optical circulator, a chirp fiber Bragg grating and a photoelectric detector. By adjusting the distance between a reflector in the MEMS interferometer and the chirped fiber bragg grating, the optical path of a second optical signal output by the MEMS interferometer transmitted to the chirped fiber bragg grating can be changed, and the delay of the chirped fiber bragg grating to the second optical signal and the free spectrum range of the interference spectrum of the MEMS interferometer can be changed. Therefore, the preset frequency range of the microwave photonic filter is changed, and single-passband frequency tuning is realized. Moreover, the MEMS interferometer and the chirped fiber Bragg grating are small in size, the size of the microwave photonic filter can be greatly reduced, meanwhile, the microwave photonic filter is more stable and reliable based on the MEMS interferometer, and controllable frequency tuning and controllable frequency range of a single passband can be achieved.

A microwave photonic filter, MWP filter, for bandpass filtering. The MWP filter includes a distributed feedback resonator structure comprising a first resonant cavity and a second resonant cavity, wherein the distributed feedback resonator structure is configured such that an input optical signal is filtered by the first resonant cavity and second resonant cavity to generate a filtered output optical signal. The MWP filter further includes a first micro heater configured to adjust the temperature of the first resonant cavity and a second micro heater configured to adjust the temperature of the second resonant cavity. The MWP filter further includes at least one of: a general heater configured to adjust the temperature of the distributed feedback resonator structure; and a tuneable continuous wave laser source, wherein the MWP filter is configured to tune a wavelength of light generated by the tuneable continuous wave laser source and used by the MWP filter.

The invention belongs to the technical field of microwave photonics, and particularly provides a microwave photonic filter based on a stimulated Brillouin scattering effect, which is used for solving the problems that the bandwidth is difficult to flexibly control, the relative intensity of each piece of pump light is difficult to control and the like in the existing microwave photonic filter based on the stimulated Brillouin scattering effect. The BPSK is used for modulating the pump light, flexible reconstruction of a filter passband can be achieved by adjusting the pulse modulation rate B or changing the P value, and meanwhile good tunability is achieved; besides, the lower light sideband generated by phase modulation is processed by utilizing the Brillouin loss spectrum in the MPF, so that the saturation effect generated by the Brillouin gain spectrum can be effectively avoided, and the input dynamic range of the MPF is expanded.

The invention discloses a high-stability tunable photoelectric oscillator based on photon complementary filtering, and belongs to the field of microwave photons. The photoelectric oscillator comprises a main laser module, an optical frequency comb generation module, a microwave photonic band-pass filter, a positive feedback photoelectric resonant cavity module, an optical injection locking module and an electric injection locking module. According to the invention, by utilizing the complementary characteristic of optical filtering at the transmission end and the downloading end of the same resonant ring, the optical carrier in the microwave photonic filter and the central angular frequency difference of the band-stop optical filter are locked, so that the angular frequency difference between the optical carrier and the band-stop optical filter is fixed, the influence of temperature on the central frequency of the MPF is eliminated, and the MPF performance is improved. MPF output passes through a microwave amplifier, a second electric power divider and a third electric power divider to form a positive feedback photoelectric resonant cavity, and then photoelectric oscillator output is locked through an electric injection locking technology, so that the output frequency stability of the OEO is improved.

This invention discloses a wide-tunable single-passband microwave photonic filter, comprising a tunable laser source and an optical fiber coupler; the tunable laser source is connected to a polarization modulator via a polarization controller PC1, the polarization modulator is connected to a polarization beamsplitter via a polarization controller PC2, one path of the polarization beamsplitter is connected to the optical fiber coupler via a polarization controller PC3, and the other path is connected to a semiconductor laser via a polarization controller PC4, the semiconductor laser is connected to the optical fiber coupler, the optical fiber coupler is connected to a photodetector, and the photodetector is connected to the polarization modulator via a vector network analyzer.