704 results about "Lithium niobate" patented technology

The invention relates to the field of optical protection materials, and provides a transparent film with laser eavesdropping prevention performance and a preparation method thereof.The transparent film is composed of surface-modified doped tungsten oxide nanosheets, amino-isocyanate bifunctional lithium niobate nanowires, urethane acrylate, an ultraviolet light absorber, a silane coupling agent, a dispersing agent and a flatting agent; the molybdenum-doped tungsten oxide nanosheets are obtained through silane coupling modification after hydrothermal synthesis, and the lithium niobate nanowires are prepared through a gradient modification process of hydrothermal synthesis-silane coupling-isocyanate grafting-phenol end capping. A modified nano material is uniformly dispersed in a resin matrix through an ultrasonic dispersion composite technology, and through blade coating forming, ultraviolet curing and constant-temperature and constant-humidity post-treatment, compared with the prior art, the scheme overcomes the problems that a traditional protective film is insufficient in optical transparency, laser eavesdropping prevention function and dynamic viscoelasticity, and is suitable for the field of high-end security and protection.

The invention discloses a composite modified material for a lithium niobate wafer, and relates to the technical field of nano materials. The material is composed of an anti-corrosion passivation matrix and a function enhancement component, wherein the anti-corrosion matrix adopts a silicon nitride / SiO2 multi-layer composite layer, atomic layer deposition titanium dioxide and magnetron sputtering aluminum oxide to form cascade protection; the functional layer comprises lead sulfide nanoparticles and nano silicon dioxide, and is directionally modified by a silane coupling agent and a perfluoropolyether surfactant. During preparation, PbS nano-particles are synthesized by combining a PECVD-ALD-magnetron sputtering stepped deposition process (200-150 DEG C) with a solvothermal method, and finally, the PbS nano-particles are formed through spin coating-annealing (300-400 DEG C). The optical loss of the material under the wavelength of 1550 nm is smaller than 0.2 dB / cm, the acid and alkali corrosion resistance is larger than 240 h, the lead dissolution rate is smaller than 0.1 ppm, the interface state density is reduced by 2 orders of magnitude, the contradiction between lithium niobate wafer surface degradation, photoelectric property degradation and lead-containing material environment risk is solved, and the material is suitable for 5G optical waveguide and quantum integrated device packaging.

The invention relates to the technical field of optoelectronics, and discloses a compact mixed optical path high-density integration method of a multi-level waveguide composite structure, which comprises the following steps: S1, preparing a multi-material layer: sequentially depositing a silicon layer, a silicon nitride layer and a lithium niobate layer, preparing the silicon layer and the silicon nitride layer through a chemical vapor deposition process, preparing the lithium niobate layer through direct current magnetron sputtering, and preparing the multi-material layer; the refractive indexes of the silicon layer, the silicon nitride layer and the lithium niobate layer meet gradient distribution; s2, designing an interlayer coupling structure: forming a gradient waveguide coupler at an interface of adjacent material layers to realize interlayer light field transmission; and S3, stress regulation and control layer integration: arranging a buffer layer with a matched thermal expansion coefficient between the silicon layer and the silicon nitride layer. According to the invention, the silicon layer, the silicon nitride layer and the lithium niobate layer are sequentially deposited, and the refractive index of each layer satisfies gradient distribution, so that the problems of large light field reflection and scattering loss and low coupling efficiency caused by the fact that most of the traditional multilayer waveguide structures adopt single material layers are solved.

An acoustic wave device includes a support substrate, a piezoelectric layer on the support substrate, and at least one lithium niobate layer and first and second principal surfaces opposed to each other, and first and second IDT electrodes respectively on the first and second principal surfaces. Each of the first and second IDT electrodes includes electrode fingers. A duty ratio of each of the first and second IDT electrodes is equal to or greater than about 0.6. Directions of polarization of the piezoelectric layer are inverted in a thickness direction of the piezoelectric layer.

Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate and a lithium niobate (LN) plate having front and back surfaces and a thickness ts. The back surface is attached to a surface of the substrate. A portion of the LN plate forms a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the LN plate with interleaved fingers of the IDT disposed on the diaphragm. The LN plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic wave in the diaphragm. Euler angles of the LN plate are [0°, β, 0°], where 0≤β≤60°. A thickness of the interleaved fingers of the IDT is greater than or equal to 0.8 ts and less than or equal to 2.0 ts.

The invention discloses an 8 * 8 lithium niobate array optical switch, and belongs to the technical field of integrated photon and optical communication. Comprising twenty switch units of Mach-Zehnder interferometer structures, and each switch unit is provided with a modulation arm composed of an upper bent waveguide and a lower bent waveguide and is provided with a push-pull type loading electrode. The switch units are combined in a multi-stage array mode and are connected through crossed waveguides, and the 8 * 8 array non-blocking optical switch is formed by using twenty switch units. According to the invention, the 2 * 2 optical switch units with small size and high modulation efficiency are designed, the transverse size of a modulation arm is shortened by adopting upper and lower bent waveguides, the driving voltage is reduced by combining a push-pull electrode loading technology, and finally the high-density 8 * 8 array optical switch is constructed by twenty units. By utilizing the electro-optical effect of lithium niobate, through the optimization of a bent waveguide structure and the driving of a push-pull electrode, low-power-consumption and high-speed optical path switching is realized, and a high-integration-level routing solution is provided for a high-speed optical communication system.

An electro-optic device is described. The electro-optic device includes an electro-optic component implemented on an electro-optic material having a slab and a ridge portion. The electro-optic component includes a first portion of the slab and a portion of the ridge portion. The first portion of the slab has a first height. The ridge portion has a second height greater than the first height. A passive functionality component is implemented on a second portion of the slab and is optically coupled with the electro-optic component.

A miniaturized interferometric integrated photonic gyroscope structure with top silicon oxide, middle silicon oxide and bottom silicon oxide deposited on a silicon substrate comprises broadband optical source or a semiconductor optical amplifier with silicon nitride ring resonator wavelength filter, connected with a thin film lithium niobate or piezoelectrically actuated silicon nitride phase modulator vertically coupled with a silicon nitride waveguide spiral loop. The silicon nitride waveguide spiral loop is patterned on thin bottom oxide layer with air trenches below it and connected with a germanium detector either through photonic wire bonding or vertically integrated through reflecting mirror embedded into silicon wafer. Various methods of coupling alternative materials are described and the potential of connecting several spiral waveguides for enhanced sensitivity in a gyroscope application.

A thin film lithium niobate polarizer and a manufacturing method therefor. The thin film lithium niobate polarizer comprises a substrate layer, an optical waveguide layer and an upper cladding layer; the optical waveguide layer comprises a light input port, a light output port, a slab layer and a ridge waveguide layer, the ridge waveguide layer being disposed on the slab layer; the ridge waveguide layer comprises at least one transmission waveguide section, and two ends of the transmission waveguide section are symmetrically connected with connecting waveguide sections; and the transmission waveguide section is used to filter light in a TM mode in a laser signal, and output light in a TE mode in the laser signal by means of the connecting waveguide section at the other end and the light output port, achieving separation of TM and TE components in the input laser signal, to obtain pure TE light, and thereby achieve a polarizing effect. In addition, using a thin film lithium niobate platform helps to reduce the size of a device, facilitating device integration and chip miniaturization. A standard semiconductor process is used, and the process technology is mature, so that costs can be effectively reduced, and the batch production capacity of the device is improved.

The invention relates to a laser radar on-chip integrated chip based on acousto-optic modulation, an on-chip acousto-optic scanning method and a laser radar system. A plurality of groups of interdigital transducers are arranged on the lithium niobate film, two groups of chirp IDTs respectively work at a low-frequency band and a high-frequency band, and sound waves at the low-frequency band correspondingly generate a relatively large Bragg deflection angle; and the high-frequency-band sound waves correspondingly generate a relatively small Bragg deflection angle. The two groups of IDTs work cooperatively, so that two-dimensional vector scanning of a dual-frequency broadband can be realized in a chip plane; the pair of focusing IDTs can form a focusing sound field in an action area, so that the light beam subjected to two-dimensional deflection is controllably deflected in the Z direction, and the chip is endowed with the three-dimensional scanning capability. The device is high in diffraction efficiency and low in power consumption; unification of large-range search and high-precision scanning is realized; z-axis deflection is realized by integrating a special focusing type interdigital transducer, a three-dimensional scanning function is realized on a monolithic integrated acousto-optic chip, and the structure is extremely compact.

A filter device includes first and second acoustic wave resonators each including a support, a piezoelectric layer that has an X-axis, a Y-axis, and a Z-axis that are crystal axes and is made of Y-cut lithium niobate, and an IDT electrode including first and second electrode fingers. When a thickness of the piezoelectric layer is d and a center-to-center distance of the first and second electrode fingers and the second electrode fingers adjacent to each other is p, d / p is less than or equal to 0.5. An absolute value of a first slant angle α1 differs from an absolute value of a second slant angle α2.

An acoustic wave device includes a silicon single crystal baseplate including a main surface, a piezoelectric layer directly or indirectly on the main surface of the silicon single crystal baseplate, and an IDT electrode on the piezoelectric layer and including electrode fingers. The piezoelectric layer is a lithium niobate layer. In the main surface of the silicon single crystal baseplate, a plane orientation is (111). When Euler angles in the main surface of the silicon single crystal baseplate are (φ, θ, ψ), the ψ in the Euler angles of the silicon single crystal baseplate is about −30 degrees <ψ< about 30 degrees.

The invention provides an electro-optical modulator and a modulation method thereof, the electro-optical modulator comprises a substrate, a buried oxide layer and a lithium niobate waveguide layer are sequentially stacked on the substrate, and the lithium niobate waveguide layer comprises a first optical waveguide and a second optical waveguide; the electrode layer comprises a composite traveling wave electrode and a direct-current electrode, and the direct-current electrode is arranged on one side, in the signal transmission direction, of the composite traveling wave electrode; wherein the composite traveling wave electrode comprises a metal electrode and a polymer electrode, the metal electrode is embedded into the buried oxide layer, the polymer electrode is arranged on the surface of the buried oxide layer, and the composite traveling wave electrode is arranged between the first optical waveguide and the second optical waveguide and arranged on the side faces of the first optical waveguide and the second optical waveguide respectively; wherein the direct current electrode is arranged between the first optical waveguide and the second optical waveguide. The electro-optical modulator is high in electro-optical conversion efficiency, the plasma effect caused by light field coupling is effectively avoided, and the light loss of the device is remarkably reduced.

The invention relates to the technical field of optical fiber communication, in particular to a thin-film lithium niobate electro-optical modulator of a stepped electrode, which comprises a substrate, a buffer layer, an optical waveguide, a metal electrode and a transition layer, the optical waveguide is an X-shaped or Y-shaped cutting LN film, a traditional ridge-shaped structure is adopted, the optical waveguide is bonded to the thick SiO2 buffer layer on the substrate, the film can be prepared through various technologies such as ion implantation, wafer bonding and hot slicing, and in order to improve the electro-optical overlapping coefficient and reduce light absorption loss, a silicon dioxide transition layer is used for connecting the metal electrode and the optical waveguide. The metal electrode is of a stepped structure, the electrode can effectively reduce electrical loss and obtain high bandwidth, and the electrode is used for generating an electric field in the aspect of photoelectric efficiency; the electric field is used for changing the functional characteristics of the thin-film lithium niobate layer and further changing the optical transmission characteristics of the waveguide, so that electro-optical modulation is realized. Therefore, the problem that an existing electro-optical modulator is low in modulation efficiency is solved.

The invention relates to the technical field of industrial detection, and discloses a lithium niobate metasurface defect intelligent identification method based on reactive ion beam etching, which systematically solves the problem of scarcity of experimental data through physical driving simulation and a physics-based rendering algorithm, and provides large-scale field specific training data for a deep learning model. The bidirectional coupling simulation model generates defect morphology prediction data conforming to an etching dynamics law based on real process parameters and material parameters, the prediction data is converted into a synthetic image with real microscopic image statistical characteristics by a physical rendering algorithm, and the quality and consistency of the synthetic data are ensured by an automatic labeling and statistical verification process. According to the method, the number of samples of the ternary association database is multiplied, and extreme process conditions and rare defect modes which are difficult to obtain through experimental collection are covered.

The embodiment of the present disclosure provides an optical transceiver and a manufacturing method thereof. The manufacturing method comprises the following steps: providing a substrate, wherein the substrate comprises a substrate, a buried oxygen layer and a lithium niobate layer which are sequentially stacked; the substrate comprises a light modulation area and a light detection area; etching the lithium niobate layer located in the light modulation area to form a thin film lithium niobate waveguide; removing the lithium niobate layer and part of the buried oxygen layer located in the light detection area to form a groove; the bottom of the groove exposes the substrate; forming a light absorption layer in the groove; wherein the thin film lithium niobate waveguide is used for modulating an optical signal and outputting the modulated optical signal; and the light absorption layer is used for detecting the modulated optical signal and converting the modulated optical signal into an electrical signal.

The invention relates to the technical field of spot-size converters, and discloses a lithium niobate film spot-size converter with an asymmetric trident structure and a preparation method of the lithium niobate film spot-size converter with the asymmetric trident structure. The lithium niobate film waveguide layer is positioned on the insulating layer; the silicon dioxide layer is coated on the lithium niobate film waveguide layer; the silicon nitride waveguide layer is located on the silicon dioxide layer; the silicon nitride waveguide layer comprises a first waveguide part, a second waveguide part and a third waveguide part which are connected in sequence in the direction from the input end to the output end of the lithium niobate film spot size converter, and the first waveguide part, the second waveguide part and the third waveguide part are located on the same plane; in the light wave transmission direction, the transverse size of the second waveguide part is sequentially increased, and the transverse size of the third waveguide part is sequentially reduced; according to the invention, the process preparation difficulty is low, high-efficiency coupling with the coupling efficiency of more than 90% from the silicon nitride waveguide to the lithium niobate waveguide can be realized, and the optical fiber coupling alignment tolerance and overlay tolerance as well as the overall coupling efficiency of the spot size converter are improved.

The invention provides a film lithium niobate chip optical fiber coupling machine vision alignment control method, which comprises the following steps: acquiring a high-resolution image of a waveguide end surface of a film lithium niobate chip, and extracting a multi-structure vision representation set from the high-resolution image; determining an effective action area of the mode field by combining the emergent light intensity distribution and geometric constraint provided by the boundary of the side wall; calculating an energy weighted center based on the light intensity distribution in the effective action area of the mode field, and mapping the energy weighted center to an assembly platform coordinate system to obtain an optical coupling reference center for alignment; with the optical coupling reference center as a target, the position and posture of the optical fiber are adjusted through feedback control, so that the center of an optical fiber core approaches and aligns to the optical coupling reference center; after alignment is completed, the stable optical fiber pose is evaluated and locked, the final coupling pose and performance indexes are output, the problem of decoupling of the visual reference and the real optical reference can be solved, and low-loss and high-stability coupling between the thin-film lithium niobate chip and the optical fiber is achieved.

To provide an optical waveguide element having a structure in which a proper tolerance is ensured in bonding, an optical connection loss between heterogeneous waveguides is small, and a chip size can be reduced even in the optical waveguide element obtained by bonding a low refractive index substrate and a TFLN.SOLUTION: The optical waveguide element comprises: a low refractive index substrate 1 composed of a material having a lower refractive index than that of lithium niobate (LN); a thin film 2 composed of LN and having a thickness of 1 μm or less, arranged on a part of the substrate 1, wherein an optical waveguide 10 having a higher refractive index than the substrate 1 and composed of materials other than LN is arranged on the substrate 1, at least a part of the optical waveguide 10 is continuously arranged from on the substrate 1 to on the thin film 2, the thin film 2 is shaped in slope in a thickness direction in a region (transition region) where the optical waveguide 10 crosses over an outer peripheral edge of the thin film 2, and an inclination (tanθ) of an edge is set to be 0.189 or less.SELECTED DRAWING: Figure 3

The invention discloses a non-equilibrium Michelson interferometer electric field sensor capable of automatically calibrating temperature influence, which has the characteristics of wide bandwidth, high measurement precision and small interference of distribution of an electric field to be measured, and can also automatically calibrate temperature influence and prevent a working point of the non-equilibrium Michelson interferometer electric field sensor from deviating. The electric field sensor comprises a lithium niobate substrate, the lithium niobate substrate is provided with a non-equilibrium Michelson interferometer, the non-equilibrium Michelson interferometer comprises an input and output waveguide, the input and output waveguide is connected with a first waveguide arm and a second waveguide arm which are different in length, two sides of the first waveguide arm are provided with electrodes, and the second waveguide arm is provided with electrodes. An antenna is arranged on the electrode, a first metal reflecting mirror is arranged at the tail end of the first waveguide arm, a second metal reflecting mirror is arranged at the tail end of the second waveguide arm, the first metal reflecting mirror and the second metal reflecting mirror are both arranged on the lithium niobate substrate, and the thermal expansion coefficients of the first metal reflecting mirror and the second metal reflecting mirror are different.

The invention provides an electro-optical modulator based on a slow light effect. The electro-optical modulator comprises a substrate, a bottom electrode, an insulating layer, a slow light waveguide layer, an upper cladding and a signal electrode which are sequentially stacked from bottom to top. Wherein the slow light waveguide layer is a photonic crystal waveguide based on Z-cut film lithium niobate, the photonic crystal waveguide comprises a line defect waveguide and a plurality of air holes arranged in a triangular lattice structure, and the plurality of air holes are symmetrically arranged at two sides of the line defect waveguide. A photonic band gap is formed by a two-dimensional periodic optical medium structure formed by combining air holes arranged in a triangular lattice structure and Z-cut film lithium niobate, the slow light effect is achieved, and light waves in a specific frequency range can only be spread along a line defect waveguide by introducing the line defect waveguide. According to the invention, the interaction between the light field and the electric field is enhanced, the modulation efficiency and performance of the electro-optical modulator can be remarkably improved, and the development trend of miniaturization, integration and high speed of an existing communication network is met.

The present disclosure provides an optical module including a circuit board and an optical transceiver assembly. The circuit board is provided with a hollowed-out area. The optical transceiver assembly includes a transceiver base and an optical assembly. The transceiver base includes a base body and a first support protrusion, and the base body is also provided thereon with a second support protrusion and a storage groove. The first support protrusion, the second support protrusion and the storage groove are all engaged with the hollowed-out area. The optical assembly includes a laser chip and a lithium niobate chip. The laser chip is located at a first end of the first support protrusion, and the lithium niobate chip is located at a second end of the first support protrusion. The laser chip is located in the storage groove, and the lithium niobate chip is located on the first support protrusion.

The invention provides a heterogeneous integrated sub-wavelength structure end face coupler adaptive to a single-mode optical fiber and a preparation method of the heterogeneous integrated sub-wavelength structure end face coupler, and relates to the technical field of integrated optics. The coupler comprises a substrate, an insulating layer, a waveguide layer and a cladding from bottom to top. The waveguide layer comprises an upper lithium niobate ridge waveguide and a lower lithium niobate ridge waveguide, the lower waveguide is wider than the upper waveguide, and the upper waveguide is used for connecting an external waveguide; the heterogeneous integrated coupling region comprises a silicon nitride strip conical waveguide which forms directional coupling with the lower-layer lithium niobate waveguide, so that adiabatic transfer of a light field is realized; the sub-wavelength grating regulation and control region sequentially comprises a silicon nitride tapered waveguide and sub-wavelength grating combination section, a width gradually-changing grating section and an equal-width buffer grating section. The whole structure is symmetrical about the central axis. Through the multi-section adiabatic transformation and heterogeneous integration design, efficient expansion of a mode field is achieved, the coupling efficiency with a single-mode fiber is improved, and the advantages of being insensitive to polarization, good in process compatibility and suitable for high-density integration are achieved.

The invention discloses a broadband nonlinear frequency converter which comprises a silicon dioxide coating layer, an x-cut lithium niobate film layer, a silicon dioxide buffer layer and a silicon substrate layer from top to bottom, the x-cut lithium niobate film layer is provided with a weak bending ridge waveguide, and the bending angle of the weak bending ridge waveguide is not larger than 5 degrees. According to the invention, birefringence phase matching is realized on the lithium niobate film in a weak bending waveguide form, so that broadband second harmonic generation, birefringence phase matching wavelength and matching angle correlation are realized, and an included angle between a wave vector of transmitted fundamental frequency light and a crystal optical axis is continuously and slightly changed through the weak bending film, so that the broadband second harmonic generation is realized. Therefore, birefringence phase matching of different wavelengths can be realized at different matching angles, and the purpose of broadband matching is achieved.

The application provides a Y-shaped thin film lithium niobate electro-optical modulator and a manufacturing method. A lithium niobate layer on an electro-optical modulator chip is etched into a corresponding curved waveguide structure, and two curved waveguide structures are symmetrically arranged on both sides of the Y-shaped waveguide structure, so that the heights of two light paths are consistent. The curved waveguide structure reduces the space size required by the waveguide while ensuring the waveguide length. For the waveguide with the same length, a chip with a smaller length can be used for mounting. The signal electrode and the ground electrode are arranged on both sides of each straight waveguide in the curved waveguide structure, the optical signal in the waveguide is modulated, and the modulation requirement of the electro-optical modulator is realized.

The invention discloses a lithium niobate electro-optical polarization modulator based on an adiabatic coupling structure and a modulation method thereof. The modulator comprises a first adiabatic coupling polarization beam splitting rotator, an electro-optical phase modulator and a second adiabatic coupling polarization beam splitting rotator, wherein each adiabatic coupling polarization beam splitting rotator comprises an input waveguide, an adiabatic coupler and a separation waveguide. According to the modulation method, transmission is carried out through a straight-through end in a first adiabatic coupling type polarization beam splitting rotator, and TE0 is kept unchanged; when the input light is TM0, the input light is converted into TE0 through the first adiabatic coupling type polarization beam splitting rotator and is transmitted through the cross end. And after phase modulation is carried out by the electro-optic phase modulator and beam combination is carried out by the second adiabatic coupling type polarization beam splitting rotator, output light is remapped into TE0 and TM0, and the polarization state is determined by the relative phase difference, so that dynamic regulation and control of the polarization state are realized.

The invention relates to a sweep frequency optical frequency comb generation system and a generation method. Fourier mode locking is realized through a Fourier mode locking photoelectric oscillator system. The sweep frequency optical frequency comb generation system is a closed Fourier mode-locked laser loop which is composed of a first optical amplifier, an optical fiber isolator, a broadband filter, a polarization controller, a thin film lithium niobate optical chip, a signal generator, a dispersion compensation optical fiber and a first optical coupler; and a photoelectric oscillator loop is formed by a second optical coupler, a single-mode delay optical fiber, a second optical amplifier, a photoelectric detector, a narrow-band filter, a low-noise amplifier and an electric power divider. Time domain active mode locking and Fourier mode locking are carried out on the laser resonant cavity at the same time, synchronous modulation of multiple optical frequency comb modes is achieved, sweep frequency optical frequency comb signals with high repetition frequency, high modulation speed, high coherence length and high output power are generated, and tunable optical frequency comb and high-quality high-frequency microwave signal output can be provided at the same time.

The invention relates to a resonant optical gyroscope signal detection method based on an optical switch. The resonant optical gyroscope signal detection method comprises the following steps: step 1, adopting a narrow linewidth laser as a light source; 2, the split light field enters a lithium niobate phase modulator A and a phase modulator B to be modulated by a triangular wave voltage signal, the light field subjected to phase modulation is coupled in opposite directions to enter a waveguide resonant cavity, and a photoelectric detector A and a photoelectric detector B are used at the output end of the resonant cavity to obtain a voltage signal; and voltage signals obtained by the photoelectric detector A and the photoelectric detector B are accessed to a lock-in amplifier. 3, arranging an optical switch A between the waveguide resonant cavity and the photoelectric detector A; and an optical switch b is arranged between the waveguide resonant cavity and the photoelectric detector B, so that the detection of a gyro signal is completed. The interference of polarization noise can be reduced, and the resonant frequency locking precision and the angular velocity detection sensitivity of the gyroscope are improved.

An optical transmission device includes a laser configured to generate an initial optical signal, radio-frequency signal channels configured to transmit radio-frequency modulation signal, a ground channel disposed in parallel with and connected to the radio-frequency signal channels, an input optical fiber receiving the initial optical signal, a front-end optical splitting element splitting the initial optical signal, and optical transmission units. Each optical transmission unit includes a rear-end optical splitting element connected to the front-end optical splitting element, two optical splitting paths, an optical combining element, and an output optical fiber configured to output the optical modulation signal. One of the radio-frequency signal channels is disposed between the two optical splitting paths, and two of the radio-frequency signal channels are disposed at two sides of the two optical splitting paths, to modulate the optical splitting signal with the corresponding radio-frequency modulation signal.

The invention relates to the technical field of lithium niobate wafers, in particular to a method for thinning a large-size lithium niobate wafer, which comprises the following steps: surface pretreatment: immersing the large-size lithium niobate wafer in a mixed acid solution for soaking treatment, removing the residual acid solution on the surface after soaking is completed, and then carrying out vacuum drying treatment. According to the method, the surface quality is high, scratches, damaged layers and roughness on the surface of the wafer are effectively reduced through the synergistic effect of surface pretreatment for removing impurities, temporary bonding for providing stable support, rough thinning, fine thinning and chemical mechanical polishing, the surface roughness Ra of the wafer can reach 0.2 nm or below, the flatness error is controlled within 1 [mu] m, and the product quality is improved. And the harsh requirement of a high-end optoelectronic device on the surface quality of the wafer is met.