124 results about "Multimode interference" patented technology

The invention relates to an on-chip integrated polarization beam splitter which comprises a first multi-mode interference coupler, a second multi-mode interference coupler, a first waveguide and a second waveguide. The input end of the first multimode interference coupler is connected with the input waveguide, the first output end is connected with the first end of the first waveguide, and the second output end is connected with the first end of the second waveguide; the first input end of the second multimode interference coupler is connected with the second end of the first waveguide, the second input end is connected with the second end of the second waveguide, the first output end is connected with the first output waveguide, and the second output end is connected with the second output waveguide; the first waveguide and the second waveguide are the same in length and different in width, the first waveguide and the second waveguide are each provided with a thermo-optical phase shifter, and the thermo-optical phase shifters are used for conducting thermo-optical phase modulation so that the phase difference between TE polarization and TM polarization can be integer multiples of pi. According to the invention, the polarization extinction ratio can be improved.

The invention relates to the technical field of optical communication, and provides a polarization separation rotator and optical communication equipment. The polarization separation rotator comprises an input coupling waveguide, a conical waveguide, a phase difference introduction waveguide and a multi-mode interference coupler, wherein the input coupling waveguide, the conical waveguide, the phase difference introduction waveguide and the multi-mode interference coupler are sequentially arranged in the light propagation direction; the input coupling waveguide is used for coupling an input optical signal to the tapered waveguide; the input optical signal comprises two polarization modes; the narrow end of the tapered waveguide is arranged corresponding to the input coupling waveguide, and the wide end of the tapered waveguide is arranged corresponding to the phase difference introduction waveguide; the phase difference introduction waveguide is used for splitting the polarization mode into a polarization mode with a preset angle phase difference; and the multimode interference coupler is used for separating the optical signals in the two polarization modes so as to respectively transmit the optical signals to different output ports. According to the polarization separation rotator provided by the invention, the defect of low port isolation is solved, and the port isolation is improved while the wide-spectrum working bandwidth is realized.

The invention relates to the technical field of lasers, in particular to a narrow-linewidth frequency conversion laser which comprises a DFB laser, a first end of the DFB laser is used for outputting initial fundamental frequency light; the lithium niobate outer cavity comprises a spot size converter, a transmission waveguide provided with a phase shift part, a first multi-mode interference coupler, upper and lower speech channel micro-rings, a second multi-mode interference coupler and a periodically poled waveguide which are connected in sequence, and the upper and lower speech channel micro-rings and a Bragg grating of the DFB laser form a resonant cavity; the upper and lower speech channel micro-rings reflect a part of the received light back to the DFB laser to realize self-injection locking and output the other part of the received light to the second multimode interference coupler, the fundamental frequency light passes through the periodically polarized waveguide to realize frequency conversion, and the output end of the periodically polarized waveguide outputs frequency-doubled light; the lithium niobate outer cavity further comprises two comb-shaped electrodes which are symmetrically arranged on the two sides of the periodically poled waveguide. The performance of the narrow-linewidth frequency conversion laser can be improved at least.

The present invention relates to the field of optical components, and in particular to a multi-wavelength silicon optical transmitter chip, whose input waveguide is used to input dual-band optical signals. A first multimode interference coupler is connected to the input waveguide and is used to distribute the dual-band optical signals from the input waveguide to two transmission paths. Each transmission path includes a silicon optical modulator and two second multimode interference couplers. The silicon optical modulator is connected between the two second multimode interference couplers via a waveguide. The silicon optical modulator includes a reverse bias electrode and two high-frequency electrodes, the two high-frequency electrodes being located on opposite sides of the waveguide and connected to the waveguide, and the reverse bias electrode being located in the middle of the waveguide. The high-frequency electrode includes multiple sub-electrodes arranged along a first direction, each of the multiple sub-electrodes including a main body, a connecting portion, and an end portion. The connecting portion and the end portion are connected to one side of the main body along a second direction, and the connecting portion and the end portion form a T-shaped structure. The end portion extends toward the waveguide and is connected to the waveguide. High-speed signal modulation is achieved.

A three-dimensional optical device (100) for coupling light from a single-core input fiber into a plurality of separate fiber cores of a multicore output fiber is disclosed. The optical device is formed in a photopolymer material and comprises an input waveguide (110), a plurality of output waveguides (130a-d), and a non-planar multimode interference section (120) for splitting light of a first mode (210) at a first end face (221) of the MMI section into a plurality of second modes (230a-d) at a second end face (222) of the MMI section. The plurality of second modes comprises a central mode (230a) and a plurality of peripheral modes (230b-d). Each output waveguide has a proximal end (131) separately connected to the second end face of the MMI section. A mode field diameter associated with the input waveguide and output waveguides is smaller at the proximal end than at the distal end. A distance between adjacent output waveguides is smaller at the proximal ends.

The invention relates to the technical field of integrated photons and optical communication, in particular to a film lithium niobate optical switch with high modulation efficiency, which is characterized in that a metal electrode sequentially comprises a modulation arm first electrode, a modulation arm second electrode and a modulation arm third electrode from top to bottom; the modulation arm first electrode and the modulation arm second electrode are respectively used as an upper modulation arm positive electrode and a lower modulation arm negative electrode, and the modulation arm third electrode and the modulation arm second electrode are respectively used as a lower modulation arm positive electrode and a lower modulation arm negative electrode; the modulation arm first electrode and the modulation arm third electrode are connected to lead out a first electrode pin, and the modulation arm second electrode leads out a second electrode pin; and the first grating and the second grating as well as the third grating and the fourth grating are respectively connected with two ends of the upper modulation arm and the lower modulation arm through a multimode interference device. According to the invention, low-voltage driving and high-efficiency phase regulation and control are realized in a submillimeter-level modulation region, and a foundation is laid for integration of a high-density optical switch array.

The invention discloses a broadband polarization rotation beam splitter based on a thin-film lithium niobate platform, an LN ridge waveguide structure is prepared on the thin-film lithium niobate platform, and the broadband polarization rotation beam splitter comprises five parts: two gradually-changed conical structures, a straight waveguide, an S bend, a phase shifter and a 2 * 2MMI coupler based on general interference. For TM0 input, a TM0 mode is converted into a TE1 mode through a conical structure, and then the TM0 mode is divided into two TE0 modes with the phase difference being pi; for TE0 input, the TE0 mode is kept unchanged and is divided into two TE0 modes with the phase difference of 0; under the two conditions, a phase difference of pi / 2 is introduced before multimode interference, and for TE0, the phase difference is pi / 2, so that the TE0 is output from CH2, and crosstalk in CH1 is minimized; for TM0, the phase difference is-pi / 2, resulting in the output of TM0 from CH1, minimizing crosstalk in CH2. According to the invention, mode conversion and polarization beam splitting are realized in a compact size.

A system for a waveguide-based diplexer (wavelength multiplexer / demultiplexer) and polarizer having ultra-broad bandwidth, a compact footprint, low losses, fabrication robustness and a simple single etch fabrication process. The polarizer (TE-pass) is based on the phase-matched coupling of the unwanted TM0 mode in an input waveguide to the TM1 mode in a tapered directional coupler (DC), which is then guided through a low-loss bend (180-degree) and scattered in a terminator section with low back reflections. An S-bend is added before the output for filtering any residual TM0mode present in the input waveguide. The diplexer is based on a multimode interference (MMI) coupler and is designed at the first imaging length for 1550 nm wavelength resulting in a compact MMI length. In order to improve the extinction ratio, the output ports are made asymmetric in width.

The invention belongs to the technical field of integrated photonic devices, and particularly relates to an electric tuning silicon nitride waveguide multimode interference coupler based on a two-dimensional material covering layer. In order to solve the problem that an existing silicon nitride photonic device lacks effective electro-optical regulation and control capacity, a two-dimensional material covering layer (such as molybdenum disulfide and tungsten disulfide) is integrated on the surface of a silicon nitride waveguide, and an up-and-down structure of a metal electrode-two-dimensional material-silicon dioxide cladding-silicon nitride waveguide is constructed. When external bias voltage is applied, the effective refractive index of the waveguide mode is changed through evanescent field coupling by means of the electrical refraction effect of the two-dimensional material, and active regulation and control of the optical path of the silicon nitride waveguide without the thermo-optic effect are achieved. Compared with a lithium niobate-silicon nitride heterogeneous integration scheme, the two-dimensional material with the atomic layer thickness is compatible with the CMOS technology, a complex heterogeneous bonding technology is not needed, and the advantage of monolithic integration is achieved. The device is particularly suitable for a reconfigurable optical signal processing device in a silicon-based photon integrated circuit.

The present invention provides a photonic integrated chip, a laser radar using the photonic integrated chip, and a detection method. The photonic integrated chip includes: a substrate, a first arrayed waveguide grating (AWG), a second arrayed waveguide grating (AWG), multiple multimode interference couplers (MIFs), multiple optical couplers (OFs), and a photodetector. The first arrayed waveguide grating (AWG) is used to split a transmitted laser signal to obtain multiple components of beamed transmitted signals; the MFIs are used to receive the beamed transmitted signals and transmit them to a target object to be detected, as well as receive reflected light spots and transmit them to the optical couplers. The second arrayed waveguide grating (AWG) is used to split a local laser signal to obtain multiple components of beamed local signals; the OFs are used to process the reflected light spots and the beamed local signals to obtain coupled signals; and the OFs are used to receive and process the coupled signals. This results in a photonic integrated chip for laser radars with a high chip integration density.

The present invention discloses a lithium niobate thin film phase modulator heterogeneously integrated with silicon nitride, belonging to the field of integrated optical gyroscopes; comprising a substrate, a silicon dioxide cladding, a lithium niobate thin film-silicon nitride optical waveguide core layer, and a modulation electrode; wherein the optical waveguide core layer is a ridge structure, comprising a lithium niobate thin film layer, a silicon nitride layer, and a silicon nitride carrier strip, satisfying single-mode transmission conditions; the silicon nitride carrier strip constitutes a multimode interference coupler, a bending unit, and a modulation arm; the multimode interference coupler adopts a one-to-two structure with a splitting ratio close to 1:1; the ridge waveguide structure is used for light transmission, and the multimode interference coupler unit is used for light splitting; simultaneously, three modulation electrodes generate an electric field, causing the light transmitted in the two modulation arms to undergo phase changes, thereby outputting two beams of light with a certain phase difference. Polarization is achieved based on the different binding effects of the ridge waveguide on the TE mode and the TM mode, that is, the loss of the TE mode and the TM mode in the waveguide is different, achieving a high polarization extinction ratio.

The application relates to the technical field of lasers, in particular to a semiconductor laser for a quantum gyroscope and a preparation method thereof. The semiconductor laser for the quantum gyroscope comprises a stacking structure, the stacking structure comprises an N-type substrate, an N-type cladding layer, an N-type waveguide layer, an active region, a first P-type waveguide layer and a waveguide structure which are stacked in a first direction in sequence, and the waveguide structure comprises a low-duty-cycle V-shaped groove grating, a multimode interference coupling beam splitting waveguide, a gain waveguide array, a multimode interference coupling beam combining waveguide, a high-duty-cycle V-shaped groove grating and a micro-tapered waveguide which are arranged and connected in a second direction in sequence. The application is favorable for realizing the semiconductor laser for the quantum gyroscope with high power and narrow linewidth under the premise of reducing the complexity of the device structure.

The present disclosure provides an optical module, comprising a light source, a coherent light chip and a controller, the coherent light chip comprising a first coupling port, a beam splitter set connected with the first coupling port, and a wavelength locker connected with an output end of the beam splitter set, the first coupling port being used for receiving local light generated by the light source, the beam splitter set being used for splitting the local light into multiple local light beams; the wavelength locker comprising two waveguides with different optical paths and a multimode interference coupler, the wavelength locker splitting one local light beam into two light beams, the two light beams being transmitted through the two waveguides and outputting at least two probe light beams with different phases by the multimode interference coupler; the controller acquiring optical powers of the at least two probe light beams, determining a wavelength of the local light according to the optical powers and a relationship curve of optical power and wavelength in the controller, and adjusting the wavelength of the local light output by the light source according to a wavelength difference between the wavelength of the local light and a preset wavelength. The present disclosure integrates the wavelength locker in the coherent light chip, thereby reducing the packaging complexity of the light source.

The invention discloses a lithium niobate eight-channel beam splitter capable of being used for an optical phased array. The lithium niobate eight-channel beam splitter comprises a silicon substrate, a silicon dioxide buffer layer, a lithium niobate core layer and a silicon dioxide cladding, the silicon dioxide buffer layer is attached to the silicon substrate, and the lithium niobate core layer is arranged on the silicon dioxide buffer layer; the silicon dioxide cladding is attached to the lithium niobate core layer and wraps the lithium niobate core layer; the lithium niobate core layer comprises an input section, a multi-mode interference coupling section and an output section which are connected in sequence, and the wide end of the input conical waveguide section is connected with one side of the multi-mode interference coupling section; and the wide ends of the eight output conical waveguide sections are connected with the other side of the multimode interference coupling section. The beam splitter is manufactured based on lithium niobate, is small in size, compact in structure, simple to process, large in manufacturing tolerance and high in product yield, and can realize uniform beam splitting in a working wave band.

This application provides a resonant modulator applicable to the field of optoelectronic information technology. The resonant modulator includes a substrate layer, a buried layer, a core layer, and an upper cladding layer. The core layer includes a multimode interference coupler and a connecting waveguide. The multimode interference coupler includes a multimode interference region and a main input port waveguide, a main output port waveguide, a feedback output port waveguide, and a feedback input port waveguide. The two ends of the connecting waveguide are optically connected to the feedback output port waveguide and the feedback input port waveguide, forming an optical feedback loop with the multimode interference coupler. An electro-optic modulation unit is associated with a first region of the connecting waveguide and is used to adjust the effective refractive index of the connecting waveguide by applying an electrical signal to change the resonant state of the resonant modulator. Based on the above structure, the sensitivity to coupling spacing and manufacturing errors can be reduced, and the device operating tolerance and modulation stability can be improved. This application also provides an optical computing system and a photonic integrated system.

The present invention discloses an integrated optical chip for augmented reality display and a preparation method thereof, belonging to the field of optoelectronics and display technology. The integrated optical chip includes a first end face coupler, a second end face coupler, and a third end face coupler, and the first end face coupler, the second end face coupler, and the third end face coupler are sequentially provided with a 2×2 multimode interference coupler, a microring filter, a 1×2 multimode interference coupler, an interlayer coupler, a thin-film lithium niobate phase shifter, a phase shifter control electrode, and a grating antenna array structure; wherein, the first end face coupler is used to couple an external red laser into the chip, the second end face coupler is used to couple an external blue laser into the chip, and the third end face coupler is used to couple an external green laser into the chip. This technical solution is used to solve the problem that the display system in the prior art is difficult to simultaneously meet the requirements of lightness, low power consumption, and high resolution.

The application discloses a bidirectional pumping quantum light source system, which comprises a multimode interference coupler, two asymmetric Mach-Zehnder interferometers AMZI1 and AMZI2 and a quantum light source. The input end of the multimode interference coupler is used for receiving pumping light. The first output end of the multimode interference coupler is connected with the input end of the AMZI1, and the first output end of the AMZI1 is connected with the first end of the quantum light source. The second output end of the multimode interference coupler is connected with the input end of the AMZI2, and the first output end of the AMZI2 is connected with the second end of the quantum light source, so as to form a Sagnac ring. The bidirectional pumping quantum light source system disclosed by the application utilizes the characteristics that the frequencies of pumping light and generated signal and idler photons are different in the spontaneous four-wave mixing process, embeds the asymmetric Mach-Zehnder interferometer with filtering effect into the Sagnac ring, and realizes the extraction of signal and idler photons in the Sagnac ring.

The invention relates to the technical field of multimode interference, and provides a central wavelength tunable multimode interference device which comprises an input waveguide region, a multimode interference region and an output waveguide region which are connected in sequence, the multimode interference region comprises a core layer, the core layer is made of a high-refractive-index material, and the output waveguide region is made of a high-refractive-index material. And a modulation electrode structure for modulating the refractive index of the core layer is arranged on the multimode interference region. The invention further provides a manufacturing method of the multimode interference device with the tunable central wavelength and a coherent modulator. Refractive index modulation is carried out on the core layer of the multi-mode interference area through the modulation electrode structure, in the multi-mode interference area, the effective refractive index directly determines the self-mapping point positions of different wavelengths, therefore, the effect of tunable central wavelength can be achieved through refractive index modulation, and through selection of different bias voltages, the tunable wavelength of the multi-mode interference area can be achieved. And the output effect of the optical power in the output waveguide is tuned.

The application relates to the technical field of optical fiber sensing, and discloses a miniaturized interrogator and a distributed optical fiber sensing system, which comprise a laser chip and an interrogator chip; the interrogator chip comprises a first optical port, a second optical port, a third optical port, a fourth optical port, a first polarization filter, a second polarization filter module, a selection switch, a beam splitter, a modulator, a polarization rotation beam splitter, a 1*2 multimode interference coupler, a first 2*4 multimode interference coupler, a second 2*4 multimode interference coupler, a first balanced detector, a second balanced detector, a third balanced detector and a fourth balanced detector. The integrated degree can be effectively improved, the system cost, volume and weight are reduced, the complex device coupling process is avoided, the production efficiency and consistency are improved, and the sensing performance is kept high.

The invention provides an optical mixer based on metasurface integration and a preparation method thereof, and belongs to the field of mixers. The mixer comprises a circularly polarized light beam splitter which comprises a first substrate, a liquid crystal structure, a second substrate and a nanorod array which are stacked in sequence; the nanorod array is used for separating the signal light and the local oscillation light into signal light left-handed rotation light, signal light right-handed rotation light, local oscillation light left-handed rotation light and local oscillation light right-handed rotation light; the liquid crystal structure is used for regulating and controlling the initial phases of the output left-handed light and right-handed light; the first multimode interference coupler is used for receiving and mixing the signal light left-rotation light output by the circularly polarized light beam splitter with the local oscillation light left-rotation light to obtain four paths of left-rotation polarized light components with different phases; and the second multimode interference coupler is used for receiving and mixing the right-handed light of the signal light output by the circularly polarized light beam splitter with the right-handed light of the local oscillation light to obtain four paths of right-handed polarized light components with different phases.

The application provides an electro-optical modulation structure, system, method and device, and the electro-optical modulation structure comprises: a first multimode interference coupler and a second multimode interference coupler, which are symmetrically arranged along a first direction and are respectively used for beam splitting and beam combining of light; a group of electro-optical modulation and light polarizers, comprising: a first electro-optical modulation and light polarizer and a second electro-optical modulation and light polarizer, which are symmetrically arranged along a second direction between the first multimode interference coupler and the second multimode interference coupler and are coupled based on surface plasmon polaritons, and are used for electro-optical modulation of the split light input from the first multimode interference coupler and output of the electro-optically modulated split light to the second multimode interference coupler for beam combining; and an extrinsic mode reflection structure used for connecting the first electro-optical modulation and light polarizer and the second electro-optical modulation and light polarizer. The scheme disclosed by the application reduces the area of integration of each device and is conducive to on-chip integration.

The invention discloses an optical switch device and a complex-valued optical neural network system, and belongs to the technical field of optical computing. The optical switch device is a two-input two-output device and comprises first to sixth waveguides, and first and second multimode interference couplers. Phase shifters are attached to the third waveguide and the fifth waveguide and / or the fourth waveguide and the sixth waveguide to form a group of configuration units which are used for loading real part and imaginary part data of a complex number. The phase shifter comprises a nonvolatile phase change material layer and a heating layer which are sequentially arranged from bottom to top, is used for realizing the function of the phase shifter, greatly reduces the static power consumption, improves the energy efficiency, is suitable for realizing the complex value optical neural network, and is also beneficial to large-scale integration. The complex-valued optical neural network system constructed based on the optical switch integrates input, calculation, reference and coherent detection modules, can synchronously complete amplitude and phase detection of optical signals, effectively supports complex-valued optical calculation, and has the advantages of low power consumption and high integration level.

To provide systems and methods for optofluidic analyte detection and analysis using multi-mode interference (MMI) waveguides.SOLUTION: An MMI waveguide 102 intersects three different liquid-core waveguides 104, 106 and 108 at different distances L (in the direction of propagation of light along the MMI waveguide) from the beginning of the MMI waveguide (e.g., from an optical input port of the MMI waveguide). In some embodiments, the liquid-core waveguides are configured to receive one or more liquid solutions comprising one or more fluorescence-tagged analytes to be detected by a system, such as molecules, particles, biomarkers, nucleic acids, DNA, proteins, and the like.SELECTED DRAWING: Figure 1A

The present invention discloses a four-mode mode division multiplexing / demultiplexing device based on Y-branching and multimode interference couplers. The device includes a four-mode multiplexer and a four-mode demultiplexer. The four-mode multiplexer and the four-mode demultiplexer multiplex four transmission modes through a four-mode bus waveguide. The four-mode multiplexer and the four-mode demultiplexer are mirror-symmetric structures, each composed of a dual-mode Y-waveguide, a four-mode Y-waveguide, a 2×2 single-mode input paired interferometer (MMI) type, and a 2×2 multimode input general interferometer (MMI) type basic unit. The present invention achieves four-mode multiplexing and demultiplexing by controlling the mode phase in the Y-waveguide and the MMI multimode coupler. The four-mode mode division multiplexer and demultiplexer have low loss, wide bandwidth, compact size, and wide manufacturing tolerance.

The invention discloses an ultra-compact reconfigurable light beam splitter based on reverse design, and the device comprises a multimode interference coupler which is realized based on a ridge waveguide and comprises a phase change material region, an N-type doped silicon waveguide and a P-type doped silicon waveguide, and the N-type doped silicon waveguide and the P-type doped silicon waveguide are arranged at the two sides of the phase change material region. The phase change material region is arranged on the ridge of the ridge waveguide and is obtained through reverse design; the metal electrode is used for applying voltage to the N-type doped silicon waveguide and the P-type doped silicon waveguide on the two sides of the phase change material area, so that the phase state of the phase change material in the phase change material area is changed; and the conical input waveguide and the conical output waveguide are arranged at the input end and the output end of the multimode interference coupler. The fixed light beam splitting mode of a traditional device is broken through, the light beam splitter integrates the optical regulation and control characteristics of the phase change material and the degree of freedom of a reversely designed structure, and an innovative solution with high dynamic range, low insertion loss and chip-level integration is provided for an optical interconnection system.

The invention provides an optical multimode interference coupler. According to the optical multi-mode interference coupler, the transmission waveguide of the slit structure is directly connected with the interface of the strip-shaped multi-mode waveguide, and based on the multi-mode excitation principle and the self-imaging principle of the multi-mode interference coupler, optical signals in the strip-shaped multi-mode waveguide are located at the interface in the slit single-mode waveguide; light splitting in the waveguide and transformation of a waveguide structure are completed at the same time, a traditional gradual deformation strip slit waveguide conversion structure does not need to be used, the length of an electronic component is effectively reduced, and the integration level of the device is improved. According to the invention, an input optical signal can be directly and equally divided into the two slit waveguides from the strip-shaped waveguide, and a traditional combined structure of first light splitting and then conversion is not needed. And the device has the advantages of small size, low loss, high bandwidth and the like.

The invention relates to the field of optical elements, in particular to a multifunctional silicon optical filter and a design method thereof, an optical signal enters a vertical coupling grating and is output through the output end of the vertical coupling grating, and the output end of the vertical coupling grating is connected to the input end of a first multimode interference device; the two output ends of the first multi-mode interference device are connected to the two input ends of the second multi-mode interference device through the two waveguides respectively. Two output ends of the second multimode interference device are respectively connected with the input end of the dispersion-free box type response grating and the input end of the three-channel Hilbert transform type grating filter; a signal reflected by the dispersion-free box type response grating is output through the first output waveguide; and a signal reflected by the three-channel Hilbert transform type grating filter is output through the second output waveguide. The dispersion-free box type response grating enables the optical signal to have the characteristic of high side-mode rejection ratio, and can meet the requirements of a multifunctional silicon optical filter.

The invention discloses an optical calculation multiplication structure and an optical calculation system, relates to the technical field of optical calculation, and aims to improve the optical calculation energy efficiency ratio and reduce the implementation difficulty of a photoelectric integrated structure. The optical calculation multiplication structure comprises a first multi-mode interference coupler, a second multi-mode interference coupler, at least two optical modulators, at least two optical waveguides and at least two switching devices. The input end of the first multimode interference coupler is used for coupling an optical signal; the output ends of the first multi-mode interference coupler correspond to the output ends of the second multi-mode interference coupler in a one-to-one mode, and each output end of the first multi-mode interference coupler is coupled with the corresponding input end of the second multi-mode interference coupler through the corresponding optical waveguide. The number of the output ends of the second multimode interference coupler is equal to the number of the input ends. The at least two optical modulators and the at least two optical waveguides are in one-to-one correspondence, each optical modulator is used for modulating an optical signal transmitted in the corresponding optical waveguide, and each optical modulator is coupled with an electric signal through a corresponding switching device.

The utility model discloses a multimode interference coupler based on thin film lithium niobate. The multimode interference coupler comprises a silicon-based substrate, a protective layer and an optical waveguide. The optical waveguide is composed of an input waveguide, a multimode interference area and two identical output waveguides. The multi-mode interference area is composed of a multi-mode interference area A and a multi-mode interference area B; the output waveguide is composed of an output gradual change area C, an output gradual change area D and an output straight waveguide. The input gradual change waveguide, the multimode interference area A, the multimode interference area B, the output gradual change area C and the output gradual change area D are all of isosceles trapezoid structures. According to the utility model, the additional loss is 0.009 dB under the wavelength of 1.55 [mu] m. Under the additional loss of 1dB, the bandwidth of the device is greater than 0.8 [mu] m. Compared with other MMI structures, the MMI structure provided by the utility model has the characteristics of large bandwidth, low loss and high process tolerance.

The application discloses a kind of based on super surface rectangular waveguide mode conversion device and method, for realizing TE 10 -TE 20 -TE 01 Metal waveguide mode conversion, rectangular waveguide mode conversion device includes first to fifth section waveguide, and first to second super surface structure, wherein: first, third, fifth section waveguide is used to transmit rectangular waveguide TE 10 Mode, rectangular waveguide TE 20 Mode and circular waveguide TE 01 Mode, second, fourth section waveguide is used to generate multimode interference;First super surface structure is used to realize TE 10 Mode to TE 20 Mode conversion, second super surface structure is used to realize TE 20 Mode to TE 01 Mode conversion;Second section waveguide, first super surface structure and third section waveguide constitute TE 10 -TE 20 Mode converter;Fourth section waveguide and second super surface structure constitute TE 20 -TE 01 Mode converter.The application utilizes the regulation and control ability of super surface to electromagnetic field, and rectangular waveguide TE 10 Mode can be converted into circular waveguide TE 01 Mode in smaller space.