110 results about "Wavelength-division multiplexing" patented technology

This invention belongs to the field of wavelength division multiplexing optical communication technology, specifically relating to a reverse coupler based on a thin-film lithium niobate platform. The reverse coupler includes: a lithium niobate-on-insulator substrate, a first waveguide, a second waveguide, and a coupling region. The first and second waveguides are disposed in the device layer of the lithium niobate-on-insulator substrate. The first and second waveguides are arranged in parallel along the light propagation direction within the coupling region. A periodic grating perturbation structure is disposed on the first and / or second waveguides. This reverse coupler utilizes the grating perturbation structure to ensure that the modes of the two waveguides satisfy the phase matching condition. The optical signal input to one waveguide is reverse-coupled to the falling port of the other waveguide. Utilizing the large photoelectric coefficient of lithium niobate material, this reverse coupler can tune its spectrum under specific conditions by applying a voltage.

This invention discloses a multi-wavelength Brillouin and Raman random fiber laser based on tunable broadband Raman pumping, comprising a 1.5μm Brillouin pump, a 1.45μm tunable broadband Raman pump, a wavelength division multiplexer (WDM) I, and a passive fiber. The 1.45μm tunable broadband Raman pump includes a wavelength-tunable cascaded random Raman fiber laser, a WDM II, and a single-mode fiber I. The wavelength-tunable cascaded random Raman fiber laser is injected into the single-mode fiber I through the WDM II. This multi-wavelength Brillouin and Raman random fiber laser based on tunable broadband Raman pumping provides a 1.45μm tunable broadband Raman pump source by back-Raman amplification of the broadband seed light. Working together with the 1.5μm Brillouin pump, it can achieve ultra-wideband multi-wavelength random fiber laser output. By simultaneously tuning the output wavelengths of the Brillouin pump and the Raman pump, wavelength tuning of the broadband multi-wavelength random fiber laser can be achieved.

The present application relates to the technical field of photolithography process, and more particularly to a kind of periodical scanning half-period optical waveguide grating preparation method, adopts multi-dimensional defect feature extraction and dynamic compensation algorithm, combined with the space-time synchronous modulation technology of light intensity distribution, significantly improves the defect masking efficiency;Through the multi-parameter collaborative optimization strategy under the closed-loop control architecture, the self-adaptive evolution mechanism of process parameters is formed, and the performance stability of grating structure under complex working conditions is guaranteed.The technical scheme innovates the whole process from light field modeling, motion control to defect repair, solves the common technical problems of grating period distortion and defect residue in the existing process, and provides a mass production solution for high-reliability grating devices for dense wavelength division multiplexing systems.

This invention belongs to the field of communication network convergence technology and discloses a protective wavelength spacing configuration method and a QKD and OTN co-fiber transmission system. The system includes: a QKD transmitter, a synchronous negotiation transmission unit, an OTN transmitter, a first silicon photonics integrated wavelength division multiplexing chip, a common transmission optical fiber, a second silicon photonics integrated wavelength division multiplexing chip, a QKD receiver, a quantum optical detection unit, a synchronous negotiation receiving unit, an OTN service receiving unit, and a control and management module. The control and management module executes the protective wavelength spacing configuration method. Compared with existing technologies, this invention, through the protective wavelength spacing configuration method, can dynamically determine the isolation distance based on bandwidth, temperature drift, filter roll-off, and safety margin, reducing the probability of crosstalk and Raman scattering noise from adjacent channels entering the quantum receiving window. It also makes linked decisions based on bit error rate, key generation rate, receiver count rate, OTN bit error rate, optical power, chip temperature, and alarm information, improving the adaptive capability of the co-fiber system.

This invention relates to the field of fiber optic sensing technology, specifically to a high-resolution, high-capacity fiber optic quasi-distributed sensing system and demodulation method. The system includes: an optical emission and pulse modulation module that emits narrowband laser light at a set step size, performs pulse chopping and optical amplification, and outputs optical pulses; an optical transmission and amplification module that isolates the reflected light, and guides the amplified optical pulses into a non-identical weak fiber Bragg grating array, extracting the signal light reflected from the array; within the same partition of the non-identical weak fiber Bragg grating array, signals are transmitted using wavelength division multiplexing (WDM), while between different partitions, signals are transmitted using time division multiplexing (TDM); a photoelectric conversion and data acquisition module converts the reflected optical signal into an electrical signal, performs A / D sampling and synchronous acquisition on the electrical signal; and a control processing module sends a synchronous control signal, performs time-domain signal filtering, spectral sliding filtering, and peak-finding demodulation on the acquired signal, and inverts the wavelength information of each weak fiber Bragg grating. This solves the problems of high transmission loss and low reliability in existing technologies.

The application discloses a kind of wavelength division multiplexing optical interconnection systems, comprising: multi-wavelength light source, for generating and outputting multi-wavelength continuous wave laser, multi-wavelength continuous wave laser contains the laser of multiple wavelengths with preset wavelength interval;Transmitter, for receiving multi-wavelength continuous wave laser, and each wavelength laser in multi-wavelength continuous wave laser is loaded with data to generate multi-wavelength optical signal, and each wavelength optical signal is added with unique pilot label;Receiver, for receiving multi-wavelength optical signal, and according to the pilot label carried by each wavelength optical signal, the optical signal of target wavelength is identified, and the data in the optical signal of target wavelength is locked and demodulated. Precise identification and locking of the working wavelength of micro-ring filter are realized, the problems of channel identification difficulty and wrong wavelength locking in micro-ring wavelength division multiplexing system are solved, and the stability and reliability of the overall interconnection system are improved.

This invention discloses a parallel demodulation and intelligent imaging system based on a reconfigurable fiber optic ultrasonic detection array, belonging to the field of ultrasonic / photoacoustic detection and imaging technology. A splicing and clamping type of flexibly reconfigurable fiber optic ultrasonic detection array structure is designed, using detachable slots and assembly fixtures for assembly, supporting dynamic splicing and reconfiguration of the array as needed to adapt to diverse detection environments. A wavelength division multiplexing (WDM) to time division multiplexing (TDM) high-capacity, streamlined parallel demodulation system is developed, forming a path-sharing delay system through the coordinated configuration of delay and beam combining, distinguishing multi-channel detection signals in the time domain, while maintaining small size and low cost. A sound velocity inversion-based highly intelligent calibration ultrasonic imaging algorithm is constructed, integrating a deep learning model to adaptively correct sound velocity distortion in non-uniform media, achieving high-quality imaging. This invention achieves flexible layout, streamlined link, and high-fidelity fiber optic array-based ultrasonic / photoacoustic imaging through synergistic optimization of front-end detection, mid-end demodulation, and back-end imaging.

This invention discloses a method, apparatus, device, and medium for demodulating optical tag signals, relating to the field of optical signal modulation. The method includes: acquiring a preset reference value for the intensity of the demodulated optical tag signal; performing target frequency filtering on the optical tag signal to be demodulated to obtain a filtered optical tag demodulated signal containing only the target frequency; comparing the intensity of the filtered optical tag demodulated signal containing only the target frequency with the preset reference value; and determining, based on the comparison result, whether the wavelength of the optical channel corresponding to the optical tag signal to be demodulated has deviated. This achieves low-cost, high-reliability processing of optical tag signals, effectively adapting to the low computing power characteristics of embedded microprocessors. Furthermore, it allows for rapid and accurate determination of whether the wavelength of the optical channel has deviated based on the comparison result of the demodulated signal intensity and the preset reference value, significantly improving the monitoring reliability, engineering feasibility, and application adaptability of dense wavelength division multiplexing systems based on micro-rings.

The application discloses an interference filter type multi-wavelength erbium-doped fiber laser based on optical path difference regulation, relates to the technical field of a ring-shaped tunable multi-wavelength erbium-doped fiber laser, and comprises a pump source, a wavelength division multiplexer, an erbium-doped fiber, an isolator, a first optical fiber coupler, a three-paddle polarization controller, a polarizer, a Mach-Zehnder interferometer filter containing an adjustable delay line, a black phosphorus saturable absorber and an extrusion type polarization controller which constitute a ring cavity. By connecting a 0-6.6 cm continuous adjustable delay line to one arm, the optical path difference of the filter two arms is accurately regulated, and continuous precise tuning of wavelength spacing of 0.3 nm to 1.54 nm is realized; meanwhile, by combining the nonlinear polarization rotation effect and the hybrid mode-locking mechanism of the few-layer black phosphorus, the mode-locking threshold is significantly reduced, and the long-term stability of the pulse is improved. The laser can realize stable emission of up to six wavelengths at the same time, the wavelength drift is less than 0.75 nm, and the power fluctuation is less than 7.0 dB.

A long-distance DWDM lightwave transmission system operating in the 2000 nm wavelength region is proposed that is based on the utilization of hollow core fiber configured to exhibit low loss (e.g., on the order of 0.02 dB / km) in combination with a hybrid TDFA / HDFA repeater device. Multiple concatenated spans of the combination of the hollow core fiber and hybrid TDFA / HDFA repeater device are able to provide communication over path lengths in excess of 10,000 km without the need for electronic regeneration of the propagating signals. In one case, the hollow core fiber is configured as a double-nested anti-resonant nodeless fiber (DNANF) with the number of nested structures and their various parameters optimized to provide the low loss operation in the 2000 nm region.

The utility model discloses a multi-channel wavelength division multiplexing optical receiving device, including device main part, its outside is equipped with a plurality of protection components, and the detachable connection between protection components and device main part, be equipped with the limiting component for limiting a plurality of protection components on device main part, device main part includes wavelength division multiplexer body, and the one side of wavelength division multiplexer body is installed with a plurality of terminal ends, and protection components and terminal ends are set up one -to -one correspondence, through with the geographical modularization design of protection components, make every terminal end have independent protection components, more flexible protection each terminal end, therefore, can open or close a certain terminal end alone, and do not influence other terminal ends, to guarantee the protection of every terminal end and the convenience of operation, simultaneously, protection components and device main part adopt detachable connection, can when a certain protection component is damaged, corresponding protection components are dismantled and replaced, to reduce maintenance cost.

The present disclosure discloses an optical signal receiving apparatus, an optical line terminal, an optical signal receiving system, an optical signal receiving method, and a computer-readable storage medium. The optical signal receiving apparatus is configured to receive optical signals at multiple speeds, and includes: a filter and at least one detector; the filter is disposed following an amplifier, filter characteristics of the filter are configured according to a preset wavelength range, and the filter is configured to filter out noise in optical signals amplified by the amplifier and perform wavelength division processing on the optical signals to obtain at least one optical signal corresponding to the preset wavelength range; and the at least one detector is configured to convert the at least one optical signal into an electrical signal.

The present disclosure is a parallel signal transmission system comprising: a transmission device that transmits a parallel signal by using a wavelength-multiplexed signal; a reception device that receives the wavelength-multiplexed signal from the transmission device and outputs the parallel signal; and a wavelength switching unit that is connected between the transmission device and the reception device and that changes at least one of the transmission wavelengths of the parallel signal so as to reduce the skew of the parallel signal in the reception device.

The application provides a kind of sub-aperture mosaic spectral calibration detection device and its detection method, wherein the detection device includes: broadband light source, wavelength division multiplexing device, coupler, integrating sphere and spectrometer;Detection device is used to detect large aperture telescope system, and telescope system includes primary mirror and secondary mirror;Broadband light source is used to emit broadband light beam to wavelength division multiplexing device, and wavelength division multiplexing device is used to select the frequency band of broadband light beam, and the incident light beam is transmitted to the pupil of telescope system through coupler, and is incident to focal plane after being reflected twice in primary mirror and secondary mirror of telescope system, and integrating sphere is arranged at the focal plane of telescope system, and the outgoing light beam is transmitted to spectrometer by multimode optical fiber to obtain the actual measured spectral data T (i). The application selects spectrum by wavelength division multiplexing device, and the response generated by different spectrum, finally realizes the splicing detection of system through the cooperation of three domains of space domain, time domain and frequency domain.

The application discloses a multi-path time delay estimation method based on orthogonal linear frequency modulation wave division multiplexing signals, and the process is as follows: an OCDM signal is transmitted by a transmitting end, a time domain receiving signal is obtained after the OCDM signal passes through a multi-path channel, a fractional domain Fourier transform (FrFT) is performed on the time domain receiving signal to obtain a fractional domain receiving signal, a covariance matrix of the fractional domain receiving signal is calculated after the fractional domain receiving signal is de-coherent, a subspace of the covariance matrix is decomposed and a spatial spectrum is calculated by using a MUSIC algorithm, and a time delay corresponding to a spectrum peak of the spatial spectrum is a time delay estimation value. The multi-path time delay estimation method disclosed by the application can accurately estimate a time delay of a dense multi-path channel with a Doppler effect, effectively reduces a relative root mean square error of time delay estimation, is still relatively accurate in estimating a time delay when the multi-path is dense, and has a certain resistance to a Doppler frequency offset.

The application provides an optical fiber brain-computer interface array system based on an MPO linking technology.The system is characterized in that it is composed of a transmitting assembly formed by transmitting light sources 1-1 and 1-2, a single-mode optical fiber wavelength division multiplexer 2 and an optical fiber beam splitter 3, an MPO optical fiber jumper 4, an MPO optical fiber probe 5, an optical fiber combiner 6 and a single photon detector (SPAD) 7.The application can be used to acquire diffuse reflection light information of blood oxygen changes in brain tissues, to monitor a cognitive activity of the brain in real time, to acquire brain activity signals related to brain functions, and can be widely used in the fields of new non-invasive optical brain-computer interface monitoring equipment and the like.

The utility model provides a kind of wideband tunable microwave photon frequency hopping communication system, including data transmitting device, data transmitting device includes four Mach-Zehnder modulators, and each Mach-Zehnder modulator receives the signal output by quadrature amplitude modulator;Carrier signal source outputs the carrier signal containing four different wavelengths to first wave division multiplexer, and first wave division multiplexer outputs four carrier signals to first optical switch, and first optical switch outputs four carrier signals to four Mach-Zehnder modulators, and first optical switch also receives the first control signal output by first frequency hopping sequence controller, and Mach-Zehnder modulator uses respective carrier signal to modulate received digital signal and then output;First micro electromechanical device is provided in first optical switch, and first micro electromechanical device has first mirror and can change the rotation angle of first mirror.The utility model can improve the security of data transmission, and production cost is low.

This application provides a multi-parameter fiber optic monitoring device for bolt loosening on transmission towers, belonging to the field of bolt loosening monitoring. It aims to solve the problems of existing bolt loosening monitoring schemes, such as susceptibility to strong electromagnetic interference, low integration, inability to cover the entire loosening cycle, and high false alarm rate. This device includes an integrated fiber optic grating-Fabry-Perot cavity sensor head and signal demodulation system, employing a coaxial push rod-mass block integrated linkage structure to achieve synchronous acquisition and mechanical decoupling of bolt axial displacement and triaxial vibration. Through a dual-band optical path architecture of 1310nm O-band and 1550nm C-band, combined with a dual-window wavelength division multiplexer, complete optical decoupling of the two parameters is achieved. It is equipped with dual-link independent wavelength calibration, hardware full-link synchronous triggering, and a dual-parameter mutual verification mechanism. This application is inherently resistant to strong electromagnetic interference and can achieve highly reliable monitoring of bolt loosening throughout its entire lifecycle.

This invention discloses a wavelength division multiplexing (WDM) trapping device and a method for measuring extremely weak forces in a single-beam vacuum optical trap. A fiber laser emits a laser beam, which passes sequentially along the fiber through a fiber acousto-optic modulator, a fiber beam splitter, and a 1064nm fiber collimator to obtain beam A. Beam A is transmitted through a dichroic mirror into a vacuum cavity, trapping and detecting micro / nano particles. Beams B, C, and D, obtained through multiple fiber beam splitters, a PPLN waveguide frequency doubling module, a fiber electro-optic modulator, and a 532nm fiber collimator, sequentially enter the vacuum cavity to triaxially cool the micro / nano particles in a vacuum environment. At this point, the micro / nano particles are in a stable state. A voltage is applied to the electrode plate, reducing the intensity of beam A, ultimately achieving a balance between electric field force and gravity. The electric field force is then used as the measurement value for the gravity of the micro / nano particles. This invention employs a wavelength division multiplexing method, achieving triaxial cooling, trapping, and detection with only one light source, and using optical fiber to replace most optical components, resulting in greater integration.

This invention discloses an integrated dual-mode-locked fiber laser source for dual-comb measurements, comprising: a pump source, a wavelength division multiplexer (WDM), a rare-earth ion-doped fiber, a first optical circulator, and a second optical circulator. The pump source is coupled to the rare-earth ion-doped fiber via the WDM. The first and second optical circulators are respectively connected to the two ends of the rare-earth ion-doped fiber. The first optical circulator forms a first resonant cavity with a first group of mode-locking elements, and the second optical circulator forms a second resonant cavity with a second group of mode-locking elements. The first and second resonant cavities are optically isolated from each other by the directional transmission characteristics of the first and second optical circulators, and share the pump source and the rare-earth ion-doped fiber to synchronously output two mode-locked pulses. This invention can generate two highly coherent mode-locked pulses with independently adjustable parameters using a single pump source and a single gain medium, exhibiting high integration, good stability, and strong practicality.

This utility model relates to a low-cost integrated module for a polarization-independent optical circulator and filter, comprising a first collimator, a circulator core, and a second collimator arranged sequentially. The first collimator is a four-fiber collimator, and the second collimator is a single-fiber collimator. The circulator core consists of a first polarizing beam splitter, a half-wave plate, a Faraday rotator crystal, a second polarizing beam splitter, a first filter, a first reflector, a second filter, a second reflector, and a magnetic block. The angle between the first filter and the first reflector is α; the angle between the second filter and the second reflector is also α. This design effectively realizes the circulator and wavelength division multiplexing functions during optical signal transmission. This design not only avoids unnecessary signal reflection and loss but also enhances the isolation of the optical circulator, achieving double-stage isolation. Wavelength division multiplexing can be achieved through small-angle incident light, making the optical path layout of the device more compact.

This invention relates to the field of flame detection technology and discloses a method for acquiring and detecting fiber optic flame detection signals under high-temperature combustion conditions. The steps are as follows: A fiber optic flame detection probe equipped with a double-layer protective sleeve is used to directionally acquire the optical signal directly in front of the target burner; multiple redundant transmission channels are constructed using wavelength division multiplexing (WDM) technology to transmit the optical signal in parallel to the signal processing terminal outside the furnace; the optical signal is converted into an electrical signal containing intensity, frequency, and wavelength divisions (350nm ultraviolet and 700nm infrared) using a photodetector, and then purified by voltage superposition noise reduction and band filtering; under low load conditions (below 30% of rated load), flame / no-flame characteristic learning is completed, and the frequency range, light intensity threshold, and wavelength division ratio are recorded; the electrical signal undergoes frequency filtering and secondary matching of wavelength division ratios to eliminate background interference; the filtered electrical signal is compared with the learned characteristics to output conclusions on the presence or absence of flame and the stability of combustion, achieving accurate and stable detection.

The optical module disclosed herein includes a circuit board, an optical fiber adapter, and an optical chip. The optical fiber adapter is optically connected to the optical chip via a first optical fiber. The optical chip includes a first optical modulator, a second optical modulator, a third optical modulator, a fourth optical modulator, and a wavelength division multiplexer (WDM). The WDM includes a coupler that can wavelength division multiplex a first wavelength optical signal, a second wavelength optical signal, a third wavelength optical signal, and a fourth wavelength optical signal, to multiplex four optical signals into one and couple it to the first optical fiber. This allows a single optical fiber to transmit four wavelengths of optical signals, reducing the number of optical fibers between the optical chip and the optical fiber adapter, thereby saving internal space in the optical module. The optical module disclosed herein facilitates the implementation of wavelength division multiplexing or wavelength demultiplexing in the optical chip.

This utility model relates to a wavelength division multiplexing (WDM) optical device, comprising: a substrate having opposing first and second grooves; a plurality of filters disposed within the first groove; a transparent filling medium filling the first groove, enclosing the filters, wherein the refractive index of the transparent filling medium matches that of the filters; and a plurality of lenses located at the bottom of the second groove, wherein the positions of the plurality of lenses correspond one-to-one with the positions of the plurality of filters. In this WDM optical device, the transparent filling medium enclosing the filters and matching the refractive index of the transparent filling medium to the filters, using a transparent filling medium with a refractive index matching that of the filters as the environmental medium, can avoid optical path misalignment, eliminate the need for additional structural adjustments to the filter positions, and simplify the structure of the WDM optical device.

Disclosed herein are optical amplifier devices, optical amplifier assembly, and optical amplifier systems. Example embodiments may include: a plurality of input optical ports, each being configured to receive one of a plurality of input optical signals; a plurality of output optical ports, each being configured to output one of a plurality of output optical signals; a plurality of tap photodiodes, each respectively being connected to one of the plurality of input optical ports and the plurality of output optical ports; a wavelength division multiplexer configured to receive the input optical signal from each of the plurality of input optical ports and an optical input from a laser pump device and output a plurality of pumped optical signals; a plurality of erbium-doped fiber coils, each having a first end configured to receive one of the plurality of pumped optical signals and a second end configured to output an amplified optical signal; and an optical isolator configured to receive, for each of the plurality of erbium-doped fiber coils, the amplified optical signal and output the plurality of output optical signals, wherein the plurality of output optical ports are configured to receive one of the plurality of output optical signals.