473 results about "Effective refractive index" patented technology

The invention relates to the technical field of optical fiber sensing, and provides a distributed fiber bragg grating temperature measurement method for boiler wall temperature measurement, which comprises the following steps of: firstly, preparing a sensor probe consisting of grating optical fibers, connecting the sensor probe with a demodulator, and starting the demodulator after the sensor probe is mounted; the laser is started, a wide-spectrum light source emitted by the laser enters the optical fiber, when the wall temperature of the boiler changes, the effective refractive index and the grating period of the grating are changed, then the Bragg wavelength moves, the data demodulation module detects the movement amount of the wavelength and converts the movement amount into corresponding temperature data, and the temperature data are transmitted to the optical fiber. Then analyzing, calculating and displaying the data; the temperature of the temperature measuring point of the furnace wall is measured through the sensor probe based on the fiber bragg grating, the demodulator analyzes the temperature data and displays the temperature data through the display screen, and therefore accurate temperature measurement of the furnace wall is achieved.

The invention discloses a lateral transceiving integrated optical fiber ultrasonic endoscope and a preparation method, and belongs to the field of ultrasonic endoscopic imaging. Comprising a double-clad optical fiber, an excitation film, a dielectric mirror and a sensing film. A part of the inner cladding of the optical fiber is etched into a concave spherical surface and coated with an excitation film, excitation light transmitted in the inner cladding is absorbed, and focused ultrasonic waves transmitted in the lateral direction are excited. A part of an inner cladding layer and a fiber core of the optical fiber are etched, and a Fabry-Perot (Fabry-Perot, F-P) cavity is prepared. When an ultrasonic signal laterally transmitted into the ultrasonic endoscope acts on the sensing film of the cavity, the effective refractive index and the F-P cavity length of the sensing film are changed, and the change is demodulated through signal light in the fiber core to complete ultrasonic detection. According to the lateral transmitting-receiving integrated optical fiber ultrasonic endoscope, the inner cladding is etched and coated with the excitation thin film to excite laterally focused ultrasonic waves, an F-P cavity is formed through lateral etching of the optical fiber to achieve lateral ultrasonic detection, and the lateral transmitting-receiving integrated optical fiber ultrasonic endoscope is formed.

An acoustic lens to steer an acoustic beam includes a first structure, a second structure spaced from the first structure, an array of projections disposed between the first and second structures, each projection of the array of projections extending from the first structure toward the second structure to define a respective gap between the projection and the second structure, and an actuator configured to move the first structure, the second structure, or the array of projections for collective adjustment of the respective gaps of the array of projections. Each projection is configured to define one or more respective unit cells, each unit cell having a sub-wavelength size relative to the acoustic beam to establish an effective refractive index profile for the acoustic beam between the first and second structures. The actuator is configured such that the collective adjustment of the respective gaps varies across the array of projections to spatially modify the effective refractive index profile to steer the acoustic beam.

The present disclosure relates to a light detection device and an electronic device capable of reducing reflection of incident light depending on an image height position. The light detection device includes a pixel array unit in which a plurality of pixels is arranged in a two-dimensional array. Each pixel includes: a refractive index variation layer having at least two regions in the same layer, the two regions being a first region containing a first matter and a second region containing a second matter; and a photoelectric conversion unit that photoelectrically converts light incident through the refractive index variation layer. An effective refractive index of the refractive index variation layer is configured to differ depending on an image height position of the pixel. The present disclosure can be applied in, for example, a solid-state image capturing device, a light-receiving device of a rangefinding system, or the like.

The invention relates to a high-efficiency super lens based on refractive index matching and a design method thereof. The super lens comprises a super atom structure layer and a bonding substrate layer on any surface, the difference value between the refractive index of any substrate layer and the average effective refractive index of the super-atomic structure layer is smaller than a preset value; when the super lens is designed, the relation among the average effective refractive index, the impedance and the S parameter of the super-atom structure layer is constructed, the structure parameter of the super-atom structure layer is determined based on the requirement parameter of the super lens, the preset S parameter of the super-atom structure layer is obtained based on electromagnetic simulation, and the average effective refractive index of the super-atom structure layer is calculated. And the substrate layer is used as an expected refractive index matching material and is bonded on one surface or two surfaces of the super-atomic structure layer. According to the invention, the high-efficiency super lens is obtained by using the principle of refractive index matching and processing methods such as large-area bonding, the focusing efficiency of the super lens is greatly improved, the application of the super lens is promoted, and the leap-type upgrading of optical devices in the dimensions of light weight and high performance is realized.

The invention discloses a polarization insensitive filter based on a sub-wavelength grating structure, and belongs to the technical field of integrated photonic devices. The filter comprises an input transition waveguide, a multimode waveguide grating and an output transition waveguide which are connected in sequence. The multimode waveguide grating is composed of a central sub-wavelength grating waveguide and Bragg gratings symmetrically distributed on the two sides, and the effective refractive indexes of TE polarization and TM polarization are equal by adjusting the waveguide width and duty ratio of the central sub-wavelength grating, so that the polarization sensitivity of the device is eliminated fundamentally. And the input / output transition waveguide adopts a transition mode of mixing a tapered waveguide and a sub-wavelength grating waveguide, so that low-loss mode transmission between a straight waveguide and a multimode grating is realized. According to the invention, the anisotropic equivalent medium characteristic of the sub-wavelength grating is utilized, a function of simultaneously and effectively filtering TE and TM polarization is realized, and the filter has the advantages of polarization insensitivity, flexible design, compact structure, simple process and compatibility with a CMOS (Complementary Metal Oxide Semiconductor) process, and has important application value in the fields of optical communication, optical interconnection and the like.

The invention relates to the technical field of ultrasonic sensors, and discloses an optical fiber end face integrated micro-cavity sonic sensor which comprises a seven-core optical fiber, two light propagation waveguides, a coupling waveguide, a supporting assembly, a micro disc, a light emitter and a photoelectric detector, the two light propagation waveguides are arranged on the end face of the seven-core optical fiber, the coupling waveguide is arranged between the two light propagation waveguides, and the supporting assembly is arranged on the end face of the seven-core optical fiber. A supporting assembly is arranged on the end face of the seven-core optical fiber, a micro disc is arranged on the top of the supporting assembly, and the first fiber core and the second fiber core are connected with an external light emitter and an external photoelectric detector respectively. The wavelength of the laser output by the light emitter is locked at the linear slope of the micro-disk harmonic peak, the radius and the effective refractive index of the micro-disk are changed through the action of ultrasonic waves on the micro-disk and vibration, the harmonic peak drifts and the intensity of the output laser is changed, and then the ultrasonic waves are detected; compared with the prior art, ultrasonic waves are detected through a micro-disk resonance and laser sideband locking method, and the problem of electromagnetic interference can be effectively avoided by utilizing the optical principle.

The disclosure proposes a polarization-independent phase modulator, a wavelength selective switch comprising the phase modulator, and a corresponding method for operating said devices. The phase modulator comprises: a LC layer; a retarder layer provided on the LC layer, wherein the LC layer and the retarder layer are divided into an array of pixels, each pixel being arranged to receive a wavelength channel of one or more wavelength channels, having a respective effective refractive index at the wavelength channel in the LC layer, and comprising a respective one or more retardance properties in the retarder layer that are adapted to the wavelength channel; a reflective layer provided on the retarder layer; an array of electrodes provided on or in the reflective layer; and a controller configured to individually control each electrode of the array of electrodes to regulate the respective effective refractive indices of at least some pixels.

An optical semiconductor device of the present disclosure has an effective refractive index nc, a wavelength λ, and an anti-reflection film formed of i coating films. The thickness of the kth coating film (1≤k≤i) is set at a value other than λ / 2 / nk. The refractive index of one or more coating films is greater than a refractive index nf which is the square root of nc. The refractive index of one or more coating films is smaller than nf. A characteristic matrix of the multilayer coating film is equal to that of a single-layer coating film of which a refractive index is nf and a thickness df is λ / 4 / nf. The thicknesses of (i−3) coating films are set in advance. The thicknesses of the remaining three coating films are determined by solutions of three simultaneous equations derived from the characteristic matrix of the multilayer coating film.

The invention discloses a super-lens design method based on etching uniformity compensation and an optimization system thereof. The super-lens design method specifically comprises the following steps: S1, etching a wafer and establishing an etching rate space distribution model; S2, designing layout partitions and distributing compensation coefficients; s3, pre-compensating the size of the nano structure; s4, generating a final mask and executing etching; according to the method, the space size pre-compensation of the nano structure is actively performed in the mask design stage, and the phase deviation caused by non-uniform etching depth is counteracted by using the change of the effective refractive index of the nano unit, so that the high-performance super lens is obtained under the non-ideal process condition, and the limitation of the process physical limit is broken through.

A semiconductor heterostructure for an optoelectronic device with improved light emission is disclosed. The heterostructure can include a first semiconductor layer having a first index of refraction n1. A second semiconductor layer can be located over the first semiconductor layer. The second semiconductor layer can include a laminate of semiconductor sublayers having an effective index of refraction n2. A third semiconductor layer having a third index of refraction n3 can be located over the second semiconductor layer. The first index of refraction n1 is greater than the second index of refraction n2, which is greater than the third index of refraction n3.

An optical device includes a transition unit in which a first waveguide and a second waveguide are disposed in an overlapped manner such that a magnitude relationship of an effective refractive index between the vertical modes propagating the first waveguide and the vertical modes propagating the second waveguide is inverted at the positions of input and output. The transition unit allows, at the input, the second waveguide to be a single mode waveguide and allows, at the output, the second waveguide to be a multi-mode waveguide through which TM0 light in the maximum vertical mode and light in a higher-order mode propagate. The optical device includes a removing unit that allows the second waveguide to be a single mode waveguide through which the TM0 light propagates by removing the light in the higher-order mode from the light received from the transition unit.

The invention discloses a polarization beam splitter based on a silicon dioxide optical waveguide, and belongs to the technical field of photon integration. The optical fiber sequentially consists of a substrate, a lower cladding, a core layer waveguide and an upper cladding, wherein the core layer waveguide is coated by the upper cladding; the lower cladding layer and the upper cladding layer are made of silicon dioxide, the core layer waveguides have the same height, are made of germanium-doped silicon dioxide, and are composed of a first 1 * 1 MZI waveguide Core1, a middle straight waveguide Core2 and a second 1 * 1 MZI waveguide Core3; when the waveguide spacing in the middle area of the core layer waveguide is close enough, the core layer waveguide can be regarded as a grating-like structure, so that the average effective refractive indexes of a TE mode and a TM mode in the area are different, coupling and multi-mode interference of light modes are generated at the same time, and after a certain length, the TE mode and the TM mode generate a phase difference, so that the interference of the TE mode and the TM mode is reduced. And finally, carrying out polarization separation and respectively outputting from two ports. The polarization multiplexing technology of a low-refractive-index-difference platform is achieved, or unwanted polarization states are filtered out in a polarization-sensitive device.

The invention relates to the technical field of optical waveguides, and particularly provides a polarization-independent prism coupling method and a waveguide structure, an optical anisotropic material is introduced into a substrate layer, a core layer and / or a cladding in a prism coupling waveguide, and a transverse electric mode and a transverse magnetic mode in the waveguide have the same effective refractive index by adjusting the refractive index distribution of the optical anisotropic material, so that the polarization-independent prism coupling method is realized. Different polarization states in the same light beam can be coupled into an optical waveguide at the same time, prism coupling is not limited by polarization sensitivity any more, the problem that a traditional prism coupling mode is limited by phase matching constraint is solved, and light of different polarization states in the same light beam has the optimal coupling angle.

The invention relates to an optomechanical system for monitoring the mechanics of a sample, comprising: a photonic crystal (1, 2) with a substrate (1) and an array of transversally extending nanopillars (2) defining at least one row (3); a nanopillar cavity (4) for confining light and acting as a sensor for the sample; and a mirror region (5) formed in the array of nanopillars (2), the cavity (4) and the mirror region (5) being configured to prevent the propagation of light with Transverse-Magnetic (TM) polarization; the nanopillars (2) being spatially arranged to create a gradient of effective refractive index along the cavity (4), the maximum value of the effective refractive index inside the cavity (4) being lower than the effective refractive index of the mirror region (5).

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 embodiment of the invention provides an optical phased array chip and a laser radar, and the chip comprises a beam splitter which is used for carrying out the beam splitting of an inputted emergent laser beam, and obtaining a plurality of emergent laser sub-beams; the phase shifter is optically connected with the beam splitter and is used for carrying out phase modulation treatment on the emergent laser sub-beams to obtain the emergent laser sub-beams subjected to phase modulation; the optical phased-array antenna array comprises a plurality of optical antennas, and the optical antennas are optically connected with the phase shifter and used for emitting the emergent laser sub-beams subjected to phase modulation to a detection area; and the compensation structure is matched with the optical phased-array antenna array and is used for performing local temperature regulation and control on the optical phased-array antenna array so as to change the effective refractive index of the corresponding optical antennae. According to the application, far-field light spots of the transmitting antenna and the receiving antenna of the laser radar can reach design values, and the accuracy of the laser radar is improved. And the detection performance of the laser radar system is improved.

The present invention discloses a fiber-optic ultrasonic endoscope with integrated lateral transmission and reception and a preparation method, which belongs to the field of ultrasonic endoscopic imaging. It comprises a double-clad optical fiber, an excitation film, a dielectric mirror, and a sensing film. By etching part of the inner cladding of the optical fiber into a concave spherical surface and coating it with an excitation film, the excitation light transmitted in the inner cladding is absorbed and focused ultrasonic waves transmitted laterally are excited. By etching part of the inner cladding and the core of the optical fiber and preparing it into a Fabry-Perot (F-P) cavity. When the ultrasonic signal transmitted laterally into the ultrasonic endoscope acts on the sensing film of the cavity, the effective refractive index of the sensing film and the F-P cavity length change, and the signal light in the core demodulates this change to complete the detection of ultrasonic waves. The present invention etches the inner cladding and coats it with an excitation film to achieve the excitation of laterally focused ultrasonic waves, etches an F-P cavity on the side of the optical fiber to achieve the lateral detection of ultrasonic waves, and thus forms a fiber-optic ultrasonic endoscope with integrated lateral transmission and reception.

The invention provides a radiation refrigeration product, a radiation refrigeration film and a preparation method of the radiation refrigeration film, the radiation refrigeration film comprises an emission layer and an anti-reflection layer which are sequentially stacked, in the visible light wavelength range, the effective refractive indexes of air, the anti-reflection layer and the emission layer are gradually increased, the emission layer and the anti-reflection layer are both made of light-transmitting materials, and the anti-reflection layer is of a porous structure. According to the radiation refrigeration film, the emission layer is arranged, so that the radiation refrigeration film has excellent emissivity in a middle infrared band and has high transmittance in a visible light band; the anti-reflection layer with the porous structure is arranged on one side of the emission layer, and the anti-reflection layer with the porous structure is matched with the emission layer to form the radiation refrigeration film with high emissivity and high transmittance in the visible light wavelength range.

The compact reconfigurable polarization converter is characterized in that the compact reconfigurable polarization converter comprises a ridge-type silicon waveguide, and the upper surface of the ridge part of the ridge-type silicon waveguide is provided with a periodic sub-wavelength nano grating structure which is used for regulating and controlling the effective refractive index of transverse electric wave and transverse magnetic wave modes and has an inclination angle; the nanometer grating structure is made of Sb2Sb3 or Sb2S3 phase change materials, the nanometer grating structure is composed of a plurality of nanometer antennas which are the same in size and shape and parallel to one another, gaps of the nanometer grating structure are filled with SiO2 materials, an Al2O layer and a graphene heating layer are sequentially arranged on the upper surface of the nanometer grating structure and the upper surface of the SiO2 filling materials from bottom to top, and the graphene heating layer is arranged on the lower surface of the nanometer grating structure. And metal electrode palladium gold is arranged on the upper surface of the graphene heating layer and located on the two sides of the flat plate part of the ridge-type silicon waveguide. The device has the advantages that the function is reconfigurable, the size is smaller, the broadband is wider, and the power consumption is lower.

The invention discloses a dual circular polarization 3D printing multi-beam Luneberg lens antenna, which adopts a 3D printing metamaterial technology and comprises a Luneberg lens and a feed antenna, the luneberg lens comprises M spherical layers which are concentrically arranged; each spherical layer comprises a plurality of units with corresponding effective refractive indexes; each unit is composed of asymmetric dielectric rods which are mutually orthogonal in the x direction, the y direction and the z direction. The Luneberg lens with the asymmetric cross structure has different responses to incident horizontal polarization and vertical polarization, so that the Luneberg lens realizes conversion from dual-linear polarization to dual-circular polarization; the feed antenna is arranged at a polarization angle of 45 degrees relative to the x axis of the Luneberg lens; the feed antenna comprises a plurality of electromagnetic dipole antenna radiation structures, and each electromagnetic dipole antenna radiation structure introduces a first feed port and a second feed port which are orthogonally arranged. By switching the corresponding feed ports, the finally generated polarization mode of left-hand circular polarization or right-hand circular polarization can be easily changed.

The invention discloses an AlGaN-based laser diode with tunable wavelength on a single wafer and a preparation method of the AlGaN-based laser diode. A plurality of two-dimensionally arranged ridge pattern arrays are prepared by using an etching method combining a room-temperature dry method and a wet method, each ridge pattern array is provided with a plurality of different ridges, each ridge with set width and shape corresponds to a lasing wavelength, and the plurality of different ridges correspond to a plurality of different lasing wavelengths respectively; a ridge pattern array is designed according to an effective refractive index, the width and the shape of ridges influence the effective refractive index and have a limiting effect on a transverse optical mode field and a carrier, so that the band gap of an atomic-scale ultrathin quantum well light-emitting layer is influenced, the lasing wavelength is further adjusted, and the wavelength-tunable AlGaN-based laser diode on a single wafer substrate is realized; according to the invention, fine regulation and control of short lasing wavelength can be realized, the method is simple and easy to control, the production time and the growth cost are obviously reduced, and the method has wide application in the field of laser diodes with adjustable and controllable lasing wavelength.

An optical module (200). The optical module (200) comprises a circuit board (300) and a light emission component (400). The light emission component (400) comprises a substrate (910), a laser chip (920), and an adapter board (980). The power supply connection and signal connection between the substrate (910) and the laser chip (920) are achieved by means of the adapter board (980), thereby avoiding the use of wire bonding to achieve the connection between the substrate (910) and the laser chip (920). The laser chip (920) comprises a first optical waveguide (9212), a second optical waveguide (9214), and a third optical waveguide (9213). The passive third optical waveguide (9213) is butt-joined to the second optical waveguide (9214) at an output end of the first optical waveguide (9212); and the transition connection between the first optical waveguide (9212) and the second optical waveguide (9214) is achieved by means of the third optical waveguide (9213), so as to reduce the end face reflection between the first optical waveguide (9212) and the second optical waveguide (9214). By controlling the thickness and width of a waveguide core layer (9226) in the second optical waveguide (9214), the effective refractive index difference between the waveguide core layer (9226) and a cladding layer of the second optical waveguide (9214) is made smaller than the effective refractive index difference between a waveguide core layer (9221) and a cladding layer of the first optical waveguide (9212), so as to optimize the spot shape and far-field divergence angle of the laser chip (920).

The invention provides a novel perovskite cell and a preparation method thereof, the novel perovskite cell comprises an antireflection film stack layer, a glass substrate, an equivalent refraction layer, a hole transport layer, a perovskite layer, an electron transport layer and a top electrode which are arranged in sequence, the antireflection film stack layer is used for constructing refractive index transition between air and the glass substrate, and the hole transport layer is used for transmitting the hole transport layer. The absolute amount of effective light entering the battery is increased; the target effective refractive index of the equivalent refraction layer is associated with the first refractive index of the glass substrate and the second refractive index of the hole transport layer, and is used for constructing refractive index transition between the glass substrate and the hole transport layer so as to reduce the interface reflection loss of the perovskite cell; it is ensured that incident light passing through the glass substrate penetrates to the perovskite layer without significant loss. Through the superposition design, the utilization rate of light in the battery can be effectively improved, and the power generation efficiency of the battery is further improved.

The invention provides a post-manufacturing correction method based on a chalcogenide phase change material, and belongs to the field of optical communication. The method comprises the following steps: firstly, taking the surface of a silicon photonic device as a substrate layer, depositing a monocrystalline silicon material on the substrate layer, and etching a groove structure on the monocrystalline silicon material to form a silicon waveguide; secondly, sequentially depositing a chalcogenide phase change material film, an isolation layer, a resistance heating layer, an adhesion layer and a metal electrode layer on the silicon waveguide; and finally, an electric pulse is applied to the resistance heating layer to generate Joule heating, the refractive index of the chalcogenide phase change material film above the silicon waveguide is finely adjusted, the effective refractive index of the waveguide is changed, the phase of an optical signal is modulated, and the phase adjustment range is 0-pi. The phase correction mode has the characteristics of low insertion loss, high correction precision and multi-stage finishing, is simple in structure, can reduce the production cost, is suitable for CMOS (Complementary Metal-Oxide-Semiconductor Transistor) integration, is easy to match with a modern semiconductor process production line, and is suitable for industrial production and productization.

The invention provides an optical fiber sensor and a preparation method thereof and an optical fiber magnetic field sensing device.The optical fiber sensor comprises an optical fiber, a fixing part and a plurality of magnetic parts, the optical fiber is provided with a macro-bending section formed by bending, and the optical fiber is fixed through the fixing part so that the macro-bending section can be kept in a bending state; the plurality of magnetic members are respectively connected to the macro-bending section at intervals along the macro-bending section. When the optical fiber sensor is arranged in a magnetic field, the magnetic part is subjected to the action of the magnetic field, so that the macro-bending section is further bent and deformed, the macro-bending diameter and the effective refractive index difference correspondingly change, and spectrum drift is caused. The magnetic field intensity and the direction can be measured by representing the wavelength drift distance and the drift direction in the spectrum. The optical fiber sensor has the advantages of simple structure, flexible and adjustable performance, low cost, high stability and the like, and can realize accurate measurement of magnetic field intensity and direction in a complex environment.

The invention discloses a high-stability light-absorption low-reflection film which comprises a substrate layer, an Al2O3 layer, Ti layers, SiO2 layers and a hydrophobic layer, wherein the Ti layers and the SiO2 layers are alternated with each other; wherein the sum of the total optical thicknesses of the Ti layers and the SiO2 layers which are alternated with each other is greater than 4.4726; the invention further discloses a preparation method of the high-stability light-absorption low-reflection film. According to the invention, the Ti layer with a higher refractive index is creatively selected to replace a traditional black film made of a high-refractive-index material, and the high-refractive-index material and the low-refractive-index material are mutually alternated, so that the effective refractive index of the film layer is close to the refractive index of the substrate layer; the problem that the spectral reflectivity is unstable due to the fact that a thin layer is too sensitive in the plating process of a traditional light-absorbing low-reflection film is solved, and the stability, compactness and other performance of the film layer are effectively improved.

A single-mode high-nonlinearity photonic crystal fiber capable of maintaining circular polarization transmission comprises a solid fiber core and a porous cladding structure arranged periodically, and the nonlinearity of the fiber is improved by optimizing the size of the fiber core and the duty ratio of cladding air holes. The torsion rate alpha introduced in the axial direction of the optical fiber is 0-8 rad / mm to introduce 10 <-3 >-order circular birefringence to maintain the circular polarization state, and effective refractive index change curves in different modes are changed. A plurality of cladding air holes are selected on the cross section of the optical fiber for selective filling or doping to realize phase matching of a fiber core high-order mode and a plurality of cladding modes, so that the fiber core high-order mode with the refractive index changing under torsion is filtered out by means of intermode coupling, the loss of the filtered high-order mode is increased by more than two orders of magnitude, and the high-order mode loss is reduced by more than two orders of magnitude. And single-mode transmission is effectively realized. Meanwhile, the characteristics of circular polarization state transmission and high nonlinearity are kept, and the optical fiber can be applied to application research of high-precision optical fiber sensing, optical fiber lasers with special circular polarization state output and the like.

A photonics device including a waveguide and an index smoothing structure is described. The waveguide is configured to carry an optical signal and includes a thin film lithium-containing electro-optic (TFLCEO) material. The waveguide has a first portion, a transition portion, and a second portion. The optical signal has a first mode in the first portion and a second mode in the second portion. The transition portion transfers the optical signal between the first portion and the second portion and transitions between the first mode and the second mode. The index smoothing structure corresponds to the transition portion. The index smoothing structure is configured to transition a first effective index of refraction for the first mode to a second effective index of refraction for the second mode. The index smoothing structure having an intermediate effective index of refraction.

The embodiment of the invention provides a multi-physical field collaborative simulation method and device for a high-speed silicon-based electro-optical modulator, and the method comprises the steps: building a physical model of the electro-optical modulator, carrying out the simulation under different bias voltage and temperature conditions, solving a Poisson equation, a carrier continuity equation and a drift diffusion transport equation, and obtaining the corresponding carrier concentration distribution; performing small-signal simulation analysis on the model to obtain corresponding PN junction electrical characteristic parameters; performing waveguide optical mode simulation on the model to obtain corresponding electric field mode distribution and effective refractive index, and calculating the effective refractive index and absorption coefficient change of the waveguide; constructing a traveling wave electrode model, simulating the traveling wave electrode model to solve an S parameter of a traveling wave electrode, and determining a distribution parameter of the no-load traveling wave microstrip line; a load traveling wave transmission line model is constructed in combination with PN junction electrical characteristic parameters, and based on the model, the frequency response characteristics and the modulation bandwidth of the electro-optical modulator at different temperatures are determined, so that the accuracy of a simulation result can be improved.