25 results about "Mode division multiplexing" patented technology

The invention discloses a relay device and method for long-distance few-mode optical fiber communication, and belongs to the field of optical communication. According to the device, firstly, optical signals transmitted in a few-mode optical fiber are separated into a plurality of independent mode channels through a mode decomposition multiplexer; then, an adjustable light delay unit is configured in each channel, and compensation is carried out according to a difference mode group delay difference pre-calculated or actually measured by a few-mode optical fiber parameter; furthermore, a dimmable amplifier is used for amplifying the signal, power monitoring is carried out at the output end of the amplifier through an optical fiber beam splitter and a photoelectric detector, closed-loop feedback control is formed, and gain of each channel is adjusted in a self-adaptive mode to eliminate mode-dependent loss. According to the invention, signal distortion can be effectively suppressed in an optical domain, the complexity of digital signal processing of a receiving end is reduced, and the transmission distance and the transmission capacity of a few-mode optical fiber mode division multiplexing communication system are remarkably improved.

An optical communication system can include a multiplexer / demultiplexer. The multiplexer / demultiplexer can transfer a first optical data signal between a first single-mode fiber and a first propagation mode of a few-mode fiber. The first propagation mode can have a first effective refractive index. The multiplexer / demultiplexer can transfer a second optical data signal between a second single-mode fiber and a combination of a second propagation mode of the few-mode fiber and a third propagation mode of the few-mode fiber. The second propagation mode and the third propagation mode can have a same effective refractive index that differs from the first effective refractive index. During propagation within the few-mode fiber, the second optical data signal can couple bidirectionally between the second propagation mode and the third propagation mode, while being substantially isolated from the first optical data signal in the first propagation mode.

The invention provides a single-port input / output multi-state adjustable waveguide mode converter and a preparation method thereof, and belongs to the technical field of on-chip silicon-based polymer hybrid integrated waveguide mode converters. According to the invention, a double-layer MZI parallel combination structure is adopted, independent electrodes are configured at specific positions of interference arms, and corresponding modulation signals are applied, so that accurate regulation and control of an input light field are realized. When E00-mode signal light is input, the structure can dynamically realize the conversion function of three modes of E00 / E01 / E10 on the premise of keeping single-port output, and the mode conversion efficiency reaches 95%. And the device is compatible with a standard silicon-based CMOS (Complementary Metal-Oxide-Semiconductor Transistor) process, is beneficial to reducing the manufacturing cost and promoting large-scale integrated application, is suitable for the fields of a high-capacity mode division multiplexing system and multi-dimensional optical signal processing, and can meet the urgent requirements of modern optical communication on high-integration-level, reconfigurable operation and low-cost devices.

The invention provides an optical chip for atom regulation and control and a regulation and control method, and belongs to the technical field of optical signal processing. The optical chip comprises a chip substrate, an optical waveguide integrated on the chip substrate, an acousto-optic modulator, an external port and a port facing an atomic array. The acousto-optic modulator generates sound waves through an interdigital transducer, and the sound waves interact with the optical signals in the acousto-optic interaction waveguide, so that at least one of the amplitude, the phase, the polarization, the frequency, the transverse mode and the transmission direction of the optical signals is accurately adjusted. The optical chip can also be integrated with a nonlinear optical frequency conversion module for changing the frequency of the optical signal; and the optical signal multiplexing module is used for performing beam splitting, filtering, frequency division or mode division multiplexing and the like on the optical signal. The external port is used for inputting / outputting optical signals, and the port facing the atom array outputs the optical signals to the atom array in a free space light beam mode and can collect the optical signals emitted by atoms.

The invention relates to an optical neural network topology adaptive mode division multiplexing communication system and a training method, and the method provided by the invention is applied to a mode division multiplexing communication system, and is used for solving the problem that the transmission or calculation performance is reduced due to dynamic coupling crosstalk of a spatial mode caused by environmental disturbance. The method comprises the following steps: monitoring the output of an optical neural network in real time, and generating a state matrix representing mode crosstalk; extracting matrix features to construct an environment vector; through a pre-trained deep reinforcement learning network, a reconstruction action for controlling the adjustable photonic device is decided and generated according to the vector; the driving device dynamically adjusts the network physical topology to compensate crosstalk; and finally, optimizing the strategy network on line based on the reconstructed performance evaluation result to form a closed loop. According to the method, the optical neural network in the mode division multiplexing has online self-adaptive capability, the dynamic mode crosstalk can be continuously inhibited, and the stability and high performance of the system in actual deployment are guaranteed.

This invention provides a mode-division multiplexing (MDF) system, method, device, and storage medium, relating to the field of optical communication technology. The MDF system includes at least: multiple cascaded optical fiber transmission units across multiple spans and a central controller. Each optical fiber transmission unit includes multimode or few-mode fiber and a mode adjustment unit. The mode adjustment unit calculates the transmission parameters of the optical fiber transmission unit and sends these parameters to the central controller. The central controller acquires the transmission parameters of the optical fiber transmission units in each span, generates a target mode round-robin strategy for the corresponding span, and sends it to the mode adjustment unit to update the optical signal module. The central controller adaptively selects the target mode round-robin strategy based on the real-time transmission environment, adaptively adjusting each span to reduce differential mode group delay (DMD) and mode-dependent loss (MDL), adapting to different span lengths and different transmission environments, and improving the transmission performance of multimode or few-mode fiber.

The application discloses a CNN-LSTM-based phase calibration method for mode division multiplexing optical fiber communication and belongs to the technical field of optical fiber communication. By constructing a double-input CNN-LSTM hybrid neural network architecture, MIMO input signals and original target signals of mode division multiplexing optical fiber communication are acquired, data preprocessing is carried out, the spatial feature extraction capability of a convolutional neural network and the time series modeling capability of a long short-term memory network are combined, effective compensation of phase noise in long-distance strong coupling mode division multiplexing optical fiber communication is realized, complex MIMO signals are separated into real and imaginary parts and sliding window training samples are generated, and a double-branch network containing an image input layer, a convolutional layer, an LSTM layer, a deep connection layer and a self-defined phase calibration layer is constructed. The problems that the phase noise compensation capability of a traditional algorithm is limited and the convergence performance is poor under a strong coupling condition are effectively solved, and the equalization performance and transmission quality of a mode division multiplexing optical fiber communication system are significantly improved.

This invention belongs to the field of optical fiber communication technology, specifically relating to a seven-core, seven-mode mode divider multiplexer based on the mode coupling principle, comprising a substrate material, a central few-mode fiber core, and peripheral single-mode fiber cores; the central few-mode fiber core contains a high-refractive-index ring; the peripheral single-mode fiber cores include components for LP (Laser-Parse) coupling to the central few-mode fiber core. 11 The first single-mode fiber core for mode conversion is used for LP to the central few-mode fiber core. 31 The second single-mode fiber core for mode conversion is used for LP to the central few-mode fiber core. 21a The third single-mode fiber core for mode conversion is used for LP to the central few-mode fiber core. 02 The fourth single-mode fiber core for mode conversion is used for LP to the central few-mode fiber core. 21b The fifth single-mode fiber core for mode conversion and the LP for the central few-mode fiber core. 12 The sixth single-mode fiber core for mode switching. This invention features a large number of switching modes, high space utilization, low insertion loss, and high throughput.

The application discloses an optical mode selection switch, comprising a platform, the platform surface is fixedly connected with a spatial light modulator, an optical processing device and a phase modulation module, the spatial light modulator, the optical processing device and the phase modulation module are parallel to each other, the optical processing device is located between the spatial light modulator and the phase modulation module, a plurality of phase units are uniformly fixed on the phase modulation module, the phase modulation module is a mode demultiplexing element array module, and the phase unit is a mode demultiplexing device unit of the same coordinate transformation or multi-plane light field conversion. The application can carry out N mode inputs, N mode outputs, and can freely select, separate and group propagation modes, improve the freedom degree of mode selection, and is not limited to optical fiber input or spatial light input, optical fiber or spatial light output, so that the mode division multiplexing is not limited to being carried out in an optical waveguide.

The application provides a two-channel grating-assisted reverse coupler type dispersion compensator, comprising a mode division multiplexer, a reverse coupler, a straight waveguide, a tapered waveguide and a curved waveguide; the mode division multiplexer is a micro-ring-based mode division multiplexer, and the reverse coupler is a chirped grating-assisted reverse coupler; the straight waveguide is connected with the mode division multiplexer through the curved waveguide; the straight waveguide is connected with the mode division multiplexer through the tapered waveguide; the mode division multiplexer is connected with the reverse coupler through the tapered waveguide; and the straight waveguide is connected with the reverse coupler through the curved waveguide. The application separates the input light and the reflected output light by using the reverse coupling between two waveguides based on the Bragg condition, is equivalent in function to a Bragg grating with input and output separation, does not need an additional optical circulator or other light splitting devices, and reduces the integration difficulty of the device.

The invention provides an integrated photon neural mimicry computing chip based on mode division multiplexing, which comprises a multi-mode photon synapse array which comprises N * N multi-mode photon synapses arranged in an array mode, two adjacent multi-mode photon synapses arranged along a row, a first multi-mode photon synapse and a second multi-mode photon synapse arranged along a column, single-mode waveguides of the multi-mode photon synapses are connected, and single-mode waveguides of the multi-mode photon synapses are connected with single-mode waveguides of the multi-mode photon synapses; multimode waveguides of the second to Nth multimode photon synapses arranged along the column are connected; and N multi-mode photonic neurons connected with the last multi-mode waveguide of the corresponding column. According to the invention, a brand new mode division multiplexing integrated photon neural mimicry computing architecture is provided, the limitation of space stacking of a traditional single-mode device is broken through, and the optical parallel computing and neuron activation capability is really expanded by using a mode division multiplexing technology.

This application discloses a two-dimensional optical phased array based on mode division multiplexing, including an optical beamsplitter array and several sets of waveguide arrays. Each set of waveguide arrays includes several amplitude modulators, several phase modulators, several waveguide leads, a waveguide bus, several directional couplers, and several grating couplers. The amplitude modulators, phase modulators, and waveguide leads form a branch. The waveguide leads of each branch are connected to the waveguide bus through the directional couplers. The waveguide bus is connected to several grating couplers through the directional couplers. Embodiments of this application can improve the field of view and integration. This application can be widely applied in the field of optical device technology.

This invention discloses a mode-division multiplexer (MDD) based on a five-core photonic crystal fiber. The MMDD includes a substrate and an air-hole layer region disposed on the substrate. The air-hole layer region is composed of a plurality of air holes arranged in a pattern, and is divided into a core region and a cladding region, with the cladding region enclosing the core region. The core includes a main core region, a first side core region, a second side core region, a third side core region, and a fourth side core region. The main core region is located at the center of the substrate, and the first, second, third, and fourth side core regions surround the main core region. The cladding region surrounds the main core region. This invention modulates the incident light in the side core regions into coupled light in the main core region, thereby increasing the operating bandwidth of the MMDD and reducing insertion loss, while effectively shortening the device length. This makes the MMDD suitable for miniaturized and integrated optical fiber communication systems and MMDD systems.

This invention discloses a dual-input dual-output mode converter and its design method, relating to the field of micro-nano optoelectronic device technology. The device includes a silicon dioxide substrate, a top silicon layer, and a low-refractive-index cladding. The top silicon layer includes a first input waveguide, a second input waveguide, a mode conversion region, a first output waveguide, and a second output waveguide. The first and second input waveguides are connected to the first and second output waveguides respectively through the mode conversion region. The mode conversion region is divided into M×N rectangular units, which can be etched or unetched, with the etching depth being the same as the thickness of the top silicon layer. The state of the rectangular units is set by a quality factor. Based on reverse design, the device increases the mode conversion path within a limited size through reasonable division and calculation of the mode conversion region, achieving dual-input dual-output mode conversion functionality. This is of great significance for further improving the flexibility and integration of mode-division multiplexing systems.

The application provides a design method of a super-structure few-mode fiber Bragg grating single-channel filter and the filter, and comprises the following steps: calculating the guided modes which can be stably transmitted in the few-mode fiber, selecting two guided modes from the guided modes which can be stably transmitted, and selecting the guided mode with larger effective refractive index as a design guided mode; calculating the Bragg period corresponding to the double-mode filtering and the design guided mode according to the wavelength of the double-mode filtering which needs to be realized, and calculating the displacement between the spectrum reflection spectrums of the two selected guided modes; designing the wavelength of the first reflection peak center of the design guided mode and the wavelength of the second reflection peak center of the design guided mode according to the wavelength of the double-mode filtering which needs to be realized; representing the total reflection spectrum composed of the first reflection peak of the design guided mode and the second reflection peak of the design guided mode by a super-Gaussian function; and calculating the physical structure of the super-structure few-mode fiber Bragg grating according to the total reflection spectrum. The filter adopting the application can be applied to a mode division multiplexing (MDM) communication system.

This invention provides an optical chip and its control method for atomic manipulation, belonging to the field of optical signal processing technology. The optical chip includes a chip substrate, an integrated optical waveguide, an acousto-optic modulator, an external port, and a port facing the atomic array. The acousto-optic modulator generates acoustic waves using interdigitated transducers. These acoustic waves interact with the optical signal in the acousto-optic waveguide, thereby precisely adjusting at least one of the amplitude, phase, polarization, frequency, transverse mode, and transmission direction of the optical signal. The optical chip may also integrate a nonlinear optical frequency conversion module for changing the frequency of the optical signal, and an optical signal multiplexing module for processing the optical signal such as beam splitting, filtering, frequency division, or mode division multiplexing. The external port is used for inputting / outputting optical signals, while the port facing the atomic array outputs the optical signal to the atomic array as a free-space beam and can collect optical signals emitted by atoms.

A mode-insensitive 3×6 optical power divider based on an MMI structure and its fabrication method are disclosed, belonging to the field of optical power divider and fabrication technology. From bottom to top, it consists of a silicon substrate, a polymer lower cladding, a polymer waveguide core layer, and a polymer upper cladding. The polymer waveguide core layer is completely encapsulated within the polymer upper cladding, and its refractive index is greater than that of the polymer upper and cladding layers. Based on a four-cascaded MMI waveguide structure, the polymer waveguide core layer enables equal power distribution of both modes of optical power input from the three input ports across the six output ports, achieving mode insensitivity and allowing simultaneous power allocation for the fundamental mode and higher-order modes. This breaks away from traditional power dividers that can only input one port, as the three input ports further increase communication capacity. The device can be applied in mode-division multiplexing systems, enabling practical applications and large-scale mass production.

The invention provides an eight-mode multiplexer / demultiplexer based on a light field regulation and control non-degenerate mode main channel. The eight-mode multiplexer / demultiplexer is characterized in that the multiplexer / demultiplexer is composed of an eight-mode elliptical fiber core and seven single-mode circular fiber cores, wherein the eight-mode elliptical fiber core internally comprises four high-refractive-index elliptical micron columns, and the seven single-mode circular fiber cores are divided into two sections; the four elliptical micrometer columns are divided into an upper column, a lower column, a left column and a right column, the upper and lower symmetrical micrometer columns are arranged on the Y axis, and the left and right symmetrical micrometer columns are arranged on the X axis; mode light field regulation and control are realized by adopting four elliptical micron columns, and the mode degeneracy of a transmission main channel is further broken; the multiplexer / demultiplexer is designed by adopting a directional coupling method, the advantages of a pure silicon dioxide fiber core, step refractive index distribution, an elliptical fiber core and a four-micron column structure controlled by an optical field are fused, the problems of mode degeneration, mode crosstalk and loss in mode division multiplexing are solved, and MIMO-FREE operation of multiplexing and demultiplexing of eight modes with low loss and low crosstalk is realized.

The invention discloses an optical module system, a server and a photoelectric conversion method, and relates to the technical field of optical communication. In the optical module system, lasers, mode converters and detectors are in one-to-one correspondence, a mode multiplexer receives light beams with different polarization states output by different mode converters, then coupled light beams are separated through a mode demultiplexer, and the detectors convert optical signals corresponding to the separated light beams into electric signals. The transmission capacity and efficiency of the optical module are improved through multiple channels; secondly, target optical fiber links of the sending end and the receiving end are few-mode optical fiber links or multimode optical fiber links, namely, not single-mode optical fibers, so that it is guaranteed that one optical fiber can transmit light beams of multiple modes after mode conversion, mode division multiplexing is achieved, single-wavelength multiple channels are supported, newly-added wavelengths are not needed, and dependence on wavelength resources is reduced; and a modulation technology is not adopted, so that the signal processing complexity is relatively low.

This invention provides a dual-mode power beamsplitter, comprising a substrate with a top silicon layer. The top silicon layer includes an optimization region. An input waveguide is disposed at one end of the optimization region, and a first output waveguide and a second output waveguide are disposed at the other end. The first and second output waveguides output different modes. The optimization region is divided into N×M equally sized square units. By adjusting the state of the center of the square units, a non-periodic perforated array is formed to meet a predetermined output target. The output target refers to a 50:50 ratio of optical power between the first and second output waveguides. The dual-mode power beamsplitter provided by this invention can achieve a 50:50 power ratio beam split while simultaneously enabling mode switching, and can be widely used in mode-division multiplexing systems.

The application relates to a signal generation and transmission method, system and medium suitable for a high signal-to-noise ratio and high-order modulation format of an optical mode division multiplexing communication system, the method comprising the following steps: acquiring a plurality of original binary bit sequences to be transmitted; sequentially performing mapping and digital up-sampling processing to obtain a digital up-sampled complex sequence of each channel; performing delta-sigma modulation on the digital up-sampled complex sequence of each channel to generate a plurality of groups of high signal-to-noise ratio real signals of each channel; modulating the plurality of groups of high signal-to-noise ratio real signals of each channel on different optical LP modes by using a dual-polarization IQ modulator and a mode multiplexer, transmitting the signals through a few-mode optical fiber, and then performing signal receiving and demodulation to obtain a polarization complex signal of each channel; and performing inverse operation on the polarization complex signal of each channel to obtain a plurality of recovered original binary bit sequences. Compared with the prior art, the application has the advantages of improving transmission reliability and high efficiency.

The invention provides a graphene stacked and buried high-order mode all-optical switch and a preparation method thereof. The structure of the high-order mode all-optical switch comprises a substrate layer, an asymmetric three-dimensional (3D) Mach-Zehnder interferometer (MZI) core layer, a cladding layer and a graphene-PMMA multilayer structure. The 3D MZI structure can realize independent regulation and control of a basic mode (E00) and a first-order mode (E01), and the graphene-PMMA multilayer structure is characterized in that single-layer graphene is accurately arranged in a PMMA polymer material in a stacking and burying manner, so that the problem that the graphene is easy to crack in a traditional graphene transfer process is solved; and the longitudinally arranged graphene films have excellent photothermal conversion performance and thermal conductivity, so that heat can be diffused into the waveguide core layer. The invention relates to a low-power-consumption and quick-response high-order mode optical switch and a preparation method thereof, which improve the regulation and control capability of a photonic device on a multi-mode optical field and are suitable for the fields of a high-capacity mode division multiplexing technology and a multi-dimensional integrated photonic chip.

The invention discloses a compact multi-mode circulator based on silicon waveguide boundary deformation, and belongs to the field of micro-nano optoelectronic devices in an on-chip integrated mode division multiplexing system. According to the invention, high-efficiency multi-mode circulation conversion in a single device is taken as a core, a TE0 / TE1 dual-mode circulator and a TE0 / TE1 / TE2 three-mode circulator are respectively realized in an ultra-small functional area size depending on an SOI platform and an inverse design thought, low conversion loss and high mode purity in a 1550nm communication waveband and a 1530-1570nm broadband are ensured, performance stability under + / -10nm geometric deviation is realized, and the device has a wide application prospect. And special materials do not need to be introduced, a traditional CMOS process is compatible, a compact and reliable core mode regulation and control unit is provided for an on-chip mode division multiplexing system, and development of high-capacity optical communication and a photon integration loop is promoted.

A four-core main channel non-degenerate mode few-mode multiplexer / demultiplexer based on optical field regulation and control is characterized in that a transmission channel of the mode division multiplexer / demultiplexer is composed of an elliptical four-core super-mode fiber core FEC-SFC and three single-mode fiber cores, the elliptical four-core super-mode fiber core at the coordinate center serves as a transmission main channel, and the single-mode fiber cores SMF1, SMF2 and SMF3 are transmission coupling channels; the length of the transmission main channel FEC-SFC is 3.450 mm, and the lengths of the SMF1, the SMF2 and the SMF3 are 3.450 mm, 1.472 mm and 1.716 mm respectively; a low-loss and low-crosstalk non-degenerate mode super-mode and mode-preserving optical fiber (SMOF) core is designed as a main channel of a multiplexer and a demultiplexer, the mode degeneration of LP11a / LP11b is broken, the mode-preserving function is realized, a scheme for enhancing and increasing the effective refractive index difference between modes to solve the mode crosstalk is proposed, and the refractive index fiber core made of pure silicon dioxide is adopted to reduce the loss; according to the invention, multiplexing and demultiplexing of four kinds of super-modes of LP01, LP11a, LP11b and LP21b are realized, and MIMO-FREE operation is realized.