316 results about "Effective refractive index" patented technology

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.

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.

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 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.

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.

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.

The invention provides a method for measuring a coupling factor of a DFB (Distributed Feedback) laser chip, belongs to the technical field of semiconductor laser chips, and is used for solving the technical problem that a coupling factor obtained by modeling / simulation is greatly different from a real coupling factor. The method comprises the following steps: testing spectrums of a plurality of DFB laser chips in the same batch of chips, and counting a wavelength median; calculating the effective refractive index of the DFB laser chip according to the wavelength median; a coupling factor is calculated according to the effective refractive index, and the corresponding relation between the coupling factor and the wavelength difference of the dual-mode chip under the corresponding grating condition is obtained through a transmission matrix method; finding out the dual-mode chip, and testing the wavelength difference of the dual-mode chip; and substituting the wavelength difference into the corresponding relation to obtain a coupling factor. According to the method, the coupling factor of the DFB laser chip can be accurately obtained by combining actual test data with a transmission matrix method; moreover, test data is not influenced by current and temperature, and the method has very good universality and stability.

The invention discloses a marine salinity sensor based on on-chip integrated waveguide multimode interference and a manufacturing method. The marine salinity sensor comprises a silicon-based substrate, a waveguide lower cladding, a waveguide upper cladding, a single-mode waveguide core layer and a few-mode waveguide core layer, the single-mode waveguide core layer is connected with the introduction single-mode optical fiber; the few-mode waveguide core layer is connected with the leading-out single-mode optical fiber; the waveguide upper cladding is provided with a detection port for promoting external liquid to directly contact with the surface of the few-mode waveguide core layer; an optical signal is input from the leading-in single-mode optical fiber, is coupled with the at least-mode waveguide core layer through the single-mode waveguide core layer, and after entering the few-mode waveguide core layer, the optical signal excites a plurality of modes, generates inter-mode interference and then returns to the single-mode waveguide core layer to be output; the salinity change of the external liquid enables the refractive index of the liquid to change, and then the effective mode refractive index in the few-mode waveguide core layer is influenced, so that the output spectrum drifts, and the salinity information of the liquid can be inverted based on the spectrum drift amount.

An optical filter (10) according to the present disclosure comprises: a core part (13) that is covered with a cladding part (16), extends in one direction (z), and can propagate light in a plurality of waveguide modes; and a satellite part (17) that is covered with the cladding part (16), extends in the one direction (z) while separated from the core part (13), has a higher effective refractive index than the cladding part (16), and is smaller than the minimum possible size of an optical material capable of propagating light in a single mode.

A dynamically tunable optical mirror named as a resonant cavity switching (RCS) device and a refractive index modulating (RIM) device are disclosed. The RCS device is comprising a nanoporous piezoelectric III-nitride material layer, such as GaN, AlN, AlScN, AlGaScN or their alloys sandwiched between a high-reflectivity distributed Bragg reflector (DBR) and a lower-reflectivity output DBR. The RIM devise is comprising the nanoporous III-nitride material layer. The nanoporous layer, patterned with interdigital transducers (IDTs), is actuated via surface acoustic waves (SAWs) or electric fields to induce rapid, reversible modulation of its effective refractive index. This enables sub-nanosecond switching between resonant and off-resonant optical states, facilitating efficient energy extraction, optical pulse carving, or phase control.

The invention belongs to the field of continuum bound states and metasurfaces in nanometer photonics, and discloses a dielectric metasurface for realizing stable high-Q-value BIC through eigenfield disturbance. The dielectric metasurface comprises a dielectric substrate, a plurality of dielectric resonance units and a dielectric wrapping layer, the plurality of dielectric resonance units are periodically arranged on the dielectric substrate, and all the dielectric resonance units are surrounded by the dielectric wrapping layer; the structures of the dielectric resonance units are the same, the whole dielectric resonance units are in a regular quadrangular prism shape, and a vertical round hole is formed in the middle of each dielectric resonance unit. The corresponding positions of the two sides of each dielectric resonance unit in the y-axis direction are each provided with a columnar notch, one notch is a semicircular notch, and the other notch is a semi-elliptical notch. The dielectric metasurface can realize continuum bound state BIC of a high-quality Q factor; the morphology changes on the two sides of the notch are equal, so that the overall structure has a constant effective refractive index, and resonance with stable wavelength is generated; and a way is laid for the application of a low-threshold laser, an ultra-sensitive optical sensor and nonlinear optics.

A waveguide assembly includes first and second waveguides. The first waveguide includes silicon, first and second ends, an end member, and a tapered member. The end member extends from the first end. The tapered member extends from the end member to the second end. The second waveguide is optically coupled to and spaced away from the first waveguide. The second waveguide includes silicon nitride, first and second members, and a non-tapered member. The non-tapered member extends from the first member to the second member and in parallel with and opposing the tapered member. An effective refractive index of the non-tapered member matches an effective refractive index of the tapered member at a first plane. The first plane extends through the non-tapered member and the tapered member and perpendicular to a second plane. The second plane extends parallel to a direction of overlap between the first and second waveguides.

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 embodiment of the utility model discloses an optical waveguide and a near-to-eye display module, the optical waveguide comprises a waveguide substrate, and two or more grating areas with preset optical functions are arranged on the waveguide substrate; a grating structure formed by grating units which are periodically distributed is arranged in the grating area; a part of or all of the grating units comprise a first grating part and a second grating part, and each of the first grating part and the second grating part comprises at least one grating layer; and the first grating part and the second grating part have different effective refractive indexes.

To provide an onium salt used for a chemically amplified resist composition excellent in solvent solubility, having high sensitivity and high contrast, and excellent in lithography performance such as LWR, CDU, MEF, EL and DOF in photolithography using high energy rays, a chemically amplified resist composition containing the onium salt, and a pattern forming method using the chemically amplified resist composition.SOLUTION: An onium salt having the formula (1): SELECTED DRAWING: None

The application provides a wavelength division multiplexer and a silicon optical chip, which comprises a first unit and at least one second unit; the first unit is connected with each second unit through a first waveguide; an output port and a plurality of output ports are arranged on the same side of the first unit; the first unit and the plurality of second units are each provided with a wavelength interleaver; the wavelength interleaver comprises a homogeneous waveguide and a heterogeneous waveguide; the heterogeneous waveguide comprises a main body composed of a first material; a gap is arranged in the main body; the gap is filled with a second material; along the propagation direction of input light, the wavelength interleaver is provided with an input section, an input coupling section, a phase difference accumulation section, an output coupling section and an output section; the effective refractive index of the homogeneous waveguide and the effective refractive index of the heterogeneous waveguide in the phase difference accumulation section are different. The wavelength division multiplexer can be applied to the manufacture of optoelectronic devices, such as a silicon optical chip. The first unit and the second unit are in a folded layout, so that the layout of the wavelength division multiplexer on the chip is compact and modular.

The invention relates to a mode field separation high-polarization semiconductor laser and application thereof, and aims to solve the problem of low polarization degree caused by stress of an existing laser. The laser comprises a main mode field region and a coupling region which are stacked along an epitaxial growth direction. The main mode field region is used for limiting and lasing a first polarization optical mode; the coupling region is made of a high-loss material and is used for absorbing and attenuating the second polarization optical mode. The two meet the following matching conditions: the effective refractive index of the second polarization optical mode of the coupling region is matched with the effective refractive index of the specific m-order second polarization optical mode of the main mode field region, so that the second polarization optical mode is optically coupled and expanded to the coupling region to be dissipated; the effective refractive index of the first polarization optical mode of the coupling region is mismatched with the effective refractive index of the specific m-order first polarization optical mode of the main mode field region, so that the coupling region is limited in the main mode field region for stable lasing. According to the invention, a polarization-related mode filtering mechanism is utilized, so that the polarization degree and the process robustness of the laser are remarkably improved.

A semiconductor light-emitting structure includes a semiconductor substrate layer, a first limiting layer, a first waveguide layer, an active layer, a second waveguide layer, and a second limiting layer stacked in sequence. The active layer comprises a first superlattice active layer and a second superlattice active layer stacked in sequence, and the second superlattice active layer is located on a side of the first superlattice active layer away from the first waveguide layer. The semiconductor light-emitting structure further includes an insertion layer disposed between the second superlattice active layer and the first superlattice active layer. A refractive index of the insertion layer is less than an effective refractive index of the first superlattice active layer and less than an effective refractive index of the second superlattice active layer.

The invention discloses an infrared super lens with a moth eye imitating anti-reflection nano structure. The moth-eye anti-reflection metasurface, the metasurface lens and the substrate are all made of silicon materials, and the moth-eye anti-reflection metasurface and the metasurface lens are micro-nano-scale arrays and are located on the two sides of the same substrate respectively. According to the invention, the metasurface is fully utilized to finely and efficiently modulate the phase, amplitude and other characteristics of light waves, the moth-eye metasurface changes the effective refractive index of the surface and reduces the reflectivity of incident light on the silicon surface, the metasurface lens enables the phase distribution to meet the spherical wavefront contour, efficient focusing of emergent beams is realized, and the light quality is improved. All micro-nano structures have the advantage of good thermal stability based on the same substrate material, and anti-reflection and focusing effects are achieved in an extremely thin scale.

The invention discloses a dual-wavelength frequency doubling regulation and control method based on a PPLN waveguide, and relates to the technical field of nonlinear optics. The method comprises the following steps: constructing a PPLN waveguide model, and determining a fundamental frequency light mode and a frequency doubling light mode; calculating effective refractive indexes of the fundamental frequency light and the frequency doubling light at respective wavelengths; the polarization period is calculated according to the effective refractive index, any target polarization period is fixed, the target polarization period is configured to correspond to two different working wavelengths at the same time, and therefore dual-wavelength frequency doubling light with a specific wave crest interval is generated at the output end of the waveguide; the wave crest interval is regulated and controlled by selecting different polarization periods; according to the invention, dynamic control of dual-wavelength frequency multiplication output is realized by changing the size of a polarization period; the single waveguide can complete various optical function design ideas, and has certain value for research in related fields such as multi-wavelength lasers and wavelength multiplexing communication.