22 results about "Coupling length" patented technology

The invention discloses a polarization independent mode multiplexing / demultiplexing device based on a transverse sub-wavelength grating structure, and belongs to the technical field of photoelectrons. The device adopts an asymmetric directional coupler structure and mainly comprises a bus waveguide formed by a transverse sub-wavelength grating waveguide and a coupling waveguide parallel to the bus waveguide. The core is that longitudinal sub-wavelength grating waveguides with specific duty ratios are introduced to the coupling side of a bus waveguide and the two sides of a coupling waveguide, and accurate matching of dual-polarization-state effective refractive indexes and coupling lengths is achieved through combined regulation and control of geometric parameters of transverse and longitudinal gratings. And the dual-polarization fundamental mode in the coupling waveguide and the dual-polarization same-order high-order mode in the bus waveguide can realize synchronous conversion in a coupling region. The invention overcomes the defect of strong polarization correlation of the traditional device, has the advantages of polarization independence, low crosstalk, low insertion loss, compact structure, high process tolerance, easiness in mode expansion and the like, and can be used for multi-dimensional multiplexing transmission in optical communication and optical interconnection systems.

A mode insensitive 2x2 thermo-optic switch for mode division multiplexing system belongs to the technical field of planar optical waveguide devices. It is composed of a silicon substrate, a silicon dioxide lower cladding layer, a polymer core layer waveguide and a polymer upper cladding layer. The polymer core layer waveguide is composed of a first input straight waveguide and a second input straight waveguide, a first input S curved waveguide and a second input S curved waveguide, a first coupling arm straight waveguide, a second coupling arm straight waveguide and a third coupling arm straight waveguide, a first output S curved waveguide and a second output curved waveguide, and a first output straight waveguide and a second output straight waveguide. A metal modulation electrode is prepared on the polymer upper cladding layer corresponding to the second coupling arm straight waveguide. The present application realizes the channel switching of LP 01 , LP 11a and LP 11b three modes by adjusting the spacing and coupling length of the coupling arm straight waveguide and whether to apply the modulation electrode, which has important significance in the field of mode division multiplexing applications.

The invention relates to the technical field of acceleration detection, in particular to an acceleration sensor, a preparation method thereof and an acceleration sensing system. The acceleration sensor comprises a substrate; the first resonant cavity is movably arranged on the substrate; the second resonant cavity is arranged on the substrate, and the second resonant cavity and the first resonant cavity are coupled and staggered; wherein under the condition that the acceleration sensor is subjected to acceleration, the first resonant cavity moves relative to the second resonant cavity, so that the coupling length between the first resonant cavity and the second resonant cavity is changed; and the bus waveguide is arranged on the substrate, the bus waveguide is coupled with the second resonant cavity, and the bus waveguide is configured to receive the laser and output an optical signal corresponding to the coupling length. In this way, the acceleration detection precision can be improved, and the influence of external environment changes on acceleration sensing measurement is reduced.

An embodiment photonic coupler may include a first input waveguide, a second input waveguide, a first output waveguide, a second output waveguide, a coupling region in which electromagnetic fields associated with two or more of the first input waveguide, the second input waveguide, the first output waveguide, and the second output waveguide are overlapping with one another, and an electro-optic device in the coupling region that includes an index of refraction that is a first function of an applied voltage. The coupling region may have an effective coupling length, along an optical propagation direction, which is a second function of a product of a physical length of the coupling region multiplied by the index of refraction of the electro-optic device. A mixing ratio of electromagnetic energy transferred between the input and output waveguides, due to evanescent coupling, may be controlled by adjusting the voltage applied to the photonic coupler.

An eight-mode multiplexer / demultiplexer based on a refractive index step type non-degenerate mode main channel is characterized in that a transmission channel is formed by one eight-mode elliptical fiber core (EC) and seven single-mode fiber cores, and the elliptical fiber core at the coordinate center serves as a transmission main channel and penetrates through two sections; the single-mode fiber core serving as a side core is a transmission coupling channel, two ends of the single-mode fiber core are coupled, and the second section is arranged at the rear end of the longest coupling length of the first section; the length of a transmission main channel of the elliptical fiber core is 11.37 mm, the ellipticity rho of the elliptical core is 1.58, the length of a major semi-axis is 7.02 [mu] m, and the length of a minor semi-axis is 4.44 [mu] m; the length of the SMF-HG10 is 8.112 mm, the length of the SMF-HG01 is 4.976 mm, the length of the SMF-HG20 is 3.258 mm, the length of the SMF-HG11 is 1.190 mm, the length of the SMF-HG30 is 1.626 mm, and the length of the SMF-HG21 is 1.964 mm; the refractive index difference between the main modes of the multiplexer and the demultiplexer is greater than 1 * 10 <-3 >, the mode degeneracy of HG30 and HG02 is broken, and the mode preserving function is realized; the refractive index fiber core made of pure silicon dioxide is adopted to reduce loss; the side core is divided into two sections for coupling, so that low-loss and low-crosstalk multiplexing and demultiplexing of eight modes are realized, and MIMO-FREE operation is realized.

This application discloses a method, apparatus, storage medium, and lidar for obtaining etching depth. The method includes: obtaining a target etching depth corresponding to a target coupling length ratio at the center wavelength of an optical signal, wherein the target etching depth is any metric value selected from multiple etching depths for etching a waveguide; when the target coupling length ratio is the smallest coupling length ratio in the set of ratios, the target etching depth is determined as the waveguide etching depth for etching the waveguide; the set of ratios includes coupling length ratios corresponding to each etching depth in the set of multiple etching depths, and the coupling length ratio is obtained by considering the optical refractive index corresponding to each etching depth and the sensitivity of the optical refractive index to the shift of the center wavelength. Using this application, the operational stability of the optical coupler can be guaranteed, thereby ensuring the stability of the lidar system.

The present invention discloses a polarization-insensitive optical power coupler, which includes two silicon nitride vertical slit waveguide structures. The waveguide structures are divided into a silicon nitride layer structure on the left and a silicon nitride layer structure on the right in the width direction, and the intermediate slit material is between the silicon nitride layer structures. The outer side of the waveguide structure is coated with a cladding material, and the intermediate slit material and the cladding material are silicon dioxide or a low-refractive-index electro-optic polymer. The present invention controls the coupling length ratio of the quasi-TE and quasi-TM modes to about 1, can achieve polarization-independent power distribution, and at the same time, the polarization insensitivity of the device has a certain applicability, that is, polarization insensitivity.

The present invention relates to the field of optical fiber technology, and more specifically to a negative curvature annular optical fiber mode selective coupler. The coupler is composed of two identical negative curvature annular optical fibers bonded together. The bonded portion is the coupling region, and the unbonded portion forms four ports serving as input and output ports. The power ratio between the collinear output end and the cross output end is determined by the coupling length L. The cross-sections of the two negative curvature annular optical fibers are polished and then bonded together using a refractive index matching glue. By rationally designing the optical fiber structural parameters and appropriately selecting the center spacing and coupling length of the two optical fibers, the coupler can generate high-order OAM modes, including OAM 01 、OAM 11 、OAM 21 、OAM 31 There are 12 OAM modes in total. Compared with traditional fiber couplers, the present invention can still achieve higher coupling efficiency in high-order modes. By adjusting the coupling distance and input mode, it can also achieve adjustable splitting ratio and coupling mode.

The present application relates to the field of acceleration detection technology, and specifically to an acceleration sensor, a preparation method thereof, and an acceleration sensing system. The acceleration sensor includes: a substrate; a first resonant cavity movably disposed on the substrate; a second resonant cavity disposed on the substrate, the second resonant cavity coupled to the first resonant cavity and staggered; when the acceleration sensor is subjected to acceleration, the first resonant cavity moves relative to the second resonant cavity so that the coupling length between the first resonant cavity and the second resonant cavity changes; a bus waveguide disposed on the substrate, the bus waveguide coupled to the second resonant cavity, and the bus waveguide configured to receive laser light and output an optical signal corresponding to the coupling length. This improves the accuracy of acceleration detection and reduces the impact of changes in the external environment on acceleration sensing measurements.

The utility model discloses a radio frequency input coupler which comprises a coupler body, a radio frequency input connector, a radio frequency output connector and two coupler connectors. The coupler body is internally provided with a placing cavity, two side surfaces of the coupler body are respectively and correspondingly provided with radio frequency connector mounting holes, inner connecting ends of the radio frequency input connector and the radio frequency output connector respectively penetrate through the two radio frequency connector mounting holes and extend into the placing cavity, and the other side of the coupler body is provided with two coupling connector mounting holes. The inner connecting ends of the two coupling port joints respectively penetrate through the two coupling joint mounting holes and extend into the placing cavity; a placement cavity is formed in the coupler body, a PCB and a heat dissipation plate are arranged in the placement cavity, the heat dissipation plate is arranged between the PCB and the top surface of the bottom plate of the coupler body, a joint bonding pad is arranged on the top surface of the PCB, the coupling length is increased by changing one coupling line into an oblique line, meanwhile, the resistance of parameters of the coupler to process changes is improved, and the consistency and the anti-interference capability of the coupler are improved.

The application discloses a three-dimensional waveguide cross structure, and relates to the technical field of integrated optics and silicon photonics, and comprises a buried oxygen layer, a first material waveguide layer, a first silicon oxide cover layer, a second material waveguide layer and a second silicon oxide cover layer; the effective coupling length of the projection overlapping area of the first material waveguide layer on the second material waveguide layer satisfies the formula: wherein, L represents the effective coupling length, represents a coupling wavelength, and the value range of n is 1 to 2n, wherein n is an integer, and the constant is less than 1. According to the application, the position of the first material waveguide layer relative to the second material waveguide layer is adjusted, so that the power coupling of the cross port of the three-dimensional waveguide cross structure completes an integer multiple of the coupling period in propagation, thereby reducing the loss and crosstalk caused by coupling enhancement.

The invention discloses a full-light-operated optical switch based on photoisomerism, and belongs to the technical field of functional planar optical waveguide devices. The directional coupling optical device is a 2 * 2 device and is composed of a substrate layer, a buffer layer, a lower cladding layer, a core layer and an upper cladding layer from bottom to top, the core layer is composed of an input area, a directional coupling area and an output area in the optical transmission direction, and the input area is composed of a first straight waveguide, a first bent waveguide, a second straight waveguide and a second bent waveguide; the directional coupling area is composed of a fifth straight waveguide and a sixth straight waveguide, the output area is composed of a third bent waveguide, a third straight waveguide, a fourth bent waveguide and a fourth straight waveguide, extension lines of all the straight waveguides or extension lines of the straight waveguides are parallel to each other, and the input area and the output area are of symmetrical structures about the directional coupling area. Under the condition of external ultraviolet light, the refractive index of the core layer is changed, the coupling efficiency and the coupling length of light are changed, the function of the optical switch is achieved, the adjusted refractive index can be kept for a period of time, and therefore the optical switch has the memory characteristic.

The invention relates to a high-performance hollow-core anti-resonance optical fiber 3dB beam splitter and a beam splitting method thereof.The 3dB beam splitter comprises a cladding area and a fiber core area, the cladding area is of an anti-resonance structure formed by arranging a plurality of cylindrical quartz glass tubes in a symmetrical mode, transmission of light energy in a fiber core can be effectively limited, and leakage loss can be reduced; the fiber core area is arranged in the cladding area, comprises a first fiber core and a second fiber core and serves as an optical signal transmission channel. When an optical signal enters, the cladding area enables the optical signal to generate X and Y polarized light and to be periodically coupled between fiber cores, the coupling length ratio meets the condition by designing the arrangement of the glass tubes, and polarization-independent 50: 50 beam splitting is achieved. According to the invention, a short beam splitting length and a large bandwidth working range are realized, and a 200nm communication wave band is covered; polarization-independent power beam splitting is accurately realized; the cladding region is simple in structure, high in preparation feasibility and wide in application prospect in the field of optical communication.

The application discloses a cable coupling interference effect test system and method. The system comprises a simulation cable coupling effect test device; the simulation cable coupling effect test device comprises a simulation shielded cable, a receiver, a first cable interface box and a second cable interface box; the simulation cable coupling effect test device is laid within 10 cm of a field interference cable, and the coupling length is greater than 3 m; at least one of the first cable interface box and the second cable interface box adopts a coaxial cable test structure; the coaxial cable test structure is used for measuring the shield layer induced current and the core line coupling voltage of the simulation shielded cable; the receiver is connected with a core line coupling voltage interface and a current probe in a current test cabin to reflect the coupling interference effect level. The application can accurately obtain the shield layer induced current and the cable core line induced voltage generated in the field environment, thereby evaluating the electromagnetic coupling interference level of the field electromagnetic environment on the cable, and providing theoretical data support for field test electromagnetic compatibility.

The invention relates to the technical field of power systems, and discloses a cable effective coupling length analysis method, system and device based on HEMP coupling, a medium and a product, and the method comprises the steps: enabling HEMP plane waves to enter a target cable, considering the dielectric loss characteristics of the ground, determining the actual ground reflection coefficient through the complex dielectric constant of the ground and the incident angle of the HEMP plane waves, and obtaining the effective coupling length of the cable. The method comprises the steps of determining a distribution voltage of a target cable close to an actual scene along a propagation direction, performing time domain analysis on the distribution voltage, determining a coupling signal duration of an HEMP plane wave, and determining an effective coupling length of the target cable according to the coupling signal duration and a propagation speed of the HEMP plane wave along the target cable. Therefore, the measurement precision of the effective coupling length of the cable is remarkably improved, the method can be applied to different types of cables, and a powerful guarantee is provided for safe and stable operation of a power system.

The invention relates to the technical field of photoelectrons, in particular to a high-speed high-responsivity photoelectric detector based on a micro-ring resonant cavity and a preparation method of the high-speed high-responsivity photoelectric detector based on the micro-ring resonant cavity. The waveguide is etched to the N-type InP contact layer of the epitaxial layer structure by adopting a ridge waveguide structure; the micro-ring and the waveguide are arranged side by side, a preset gap width is arranged between the micro-ring and the waveguide to maintain a critical coupling state to form a resonant cavity, and a coupling structure shape design is arranged at a position where the waveguide is close to the micro-ring to increase the coupling length; the electrodes are arranged at the top and the bottom of the micro-ring epitaxial layer structure, and light is absorbed in the whole micro-ring. Therefore, the problem that a traditional PIN photoelectric detector has inherent tradeoff contradiction between responsivity and bandwidth is solved.

The present invention aims to provide a mode conversion device and a design method thereof, which can design arbitrary coupling efficiency and full width at half maximum. The present invention is a mode conversion device having a long-period grating in a core of an optical fiber capable of propagating light in at least two propagation modes, characterized in that the long-period grating satisfies a relationship of mathematical formula C1. Wherein, the full width at half maximum FWHM is a wavelength band in which the coupling efficiency is half compared to the coupling efficiency of the mode conversion of the center wavelength, C is the coupling efficiency, L c is the full coupling length, L g is the grating length, Λ is the grating pitch, and Δβ is the difference in propagation constant of the two propagation modes of the center wavelength as a target of mode conversion; [Mathematical formula C1]

The present invention discloses an ultra-wideband dual-core negative curvature optical fiber polarization beam splitter with a paperclip cladding structure, comprising an outer supporting tube layer with a radius R, an inner fiber core region, and a cladding region therebetween. The cladding region is composed of eight quartz tubes in a paperclip structure, consisting of an outer cladding tube and an inner nested nested tube. The nested tubes and the cladding tubes are both semi-oblong, formed by two straight sides and a semicircular side on one side, and are coaxially arranged. The present invention controls the beam splitting capability of the beam splitter by adjusting the effective refractive index of the four supermode modes in the two fiber cores. By adjusting the diameter of the semicircular side of the cladding tube, the mode field area is changed and the coupling length is increased, achieving a technical effect of an extinction ratio higher than 20 dB over a bandwidth of 1.34 to 1.88 μm and up to 540 nm, and a high-order mode extinction ratio greater than 100 in the 1.48 to 1.55 μm band.

The invention relates to the technical field of power systems, and discloses a method, system, equipment, medium and product for calculating the effective coupling length of a cable under HEMP irradiation, and the method comprises the steps: segmenting a target transmission cable to obtain multiple segments of sub-transmission cables, constructing an HEMP coupling simulation model of the sub-transmission cables for each segment of sub-transmission cable, and calculating the effective coupling length of the cable under HEMP irradiation. The simulation length of the sub-transmission cable is gradually increased according to the preset length step length, the coupling signal response peak value of the HEMP coupling simulation model after HEMP excitation is obtained after the preset length step length is increased every time, and the effective coupling length of the sub-transmission cable is judged according to the coupling signal response peak value change rate of the adjacent preset length step length. And the total effective coupling length of the target transmission cable is determined according to the effective coupling length of each section of sub-transmission cable, so that the accuracy and reliability of calculation of the effective coupling length of the cable under HEMP irradiation are effectively improved.

In part, the disclosure relates to an optical coupler. The optical coupler may include two ridge waveguides that include a first waveguide and a second waveguide. One or more segments of the two waveguides extend over a coupling length or other distance. One or more sections of each ridge waveguide is at least partially defined by a set of cross-sectional profiles, a plurality of sections of each ridge waveguide have a width that tapers along a length of the two ridge waveguides. Within the coupling length, a subset of the set of cross-sectional profiles may define a first pair of transition regions and a second pair of transition regions. The coupler may include a coupling region between the two ridge waveguides and spanning at least a section of the coupling length.

A Floquet-based silicon-based integrated compact polarization beam splitter comprises a silicon layer, a silicon oxide layer, a pair of coupling waveguides located on the silicon oxide layer, input ports corresponding to the coupling waveguides and output ports corresponding to the coupling waveguides, the silicon layer, the silicon oxide layer, the coupling waveguides, the input ports and the output ports are sequentially arranged from bottom to top, any input port inputs a TE mode or a TM mode, a first output port outputs the TM mode, and a second output port outputs the TE mode. Through periodical modulation of the waveguide width, the suppression of TE mode power exchange and the maximization of TM mode power exchange can be realized by regulating and controlling the phase between the coupling waveguides within the coupling length of only 6 microns.

The present invention provides a superconducting resonator for high-resolution detection of magnetic materials and a design method thereof. The method comprises: determining a magnetic material layer to be measured; determining a resonant frequency of a resonator according to the magnetic material layer to be measured; constructing a simulation model, wherein the simulation model includes a substrate; a resonator formed on the substrate, wherein microwave lines located on the substrate surface are formed at both ends of the resonator, the microwave lines forming a coplanar waveguide, and the resonator is coupled to the microwave lines; grounding layers located on the substrate surface are provided on both sides of the resonator; an initial air gap, an initial coupling length, and a length of the resonator are determined according to the resonant frequency and the material of the substrate; performing simulation using the initial air gap, initial coupling length, and length of the resonator according to the simulation model to obtain a quality factor of the resonator; adjusting the initial air gap and initial coupling length according to the quality factor until the quality factor of the resonator meets the requirement, and determining the air gap and coupling length of the resonator.