6986 results about "Waveguide" patented technology

The embodiment of the invention provides an electro-optical modulator and a light quantum computer. The electro-optical modulator comprises an electrode assembly and an optical waveguide assembly. The electrode assembly comprises a positive signal electrode, a negative signal electrode, a first grounding electrode and a second grounding electrode, and the positive signal electrode and the negative signal electrode are arranged between the first grounding electrode and the second grounding electrode. The optical waveguide assembly is configured to bear optical signals and comprises a first optical waveguide and a second optical waveguide, the first optical waveguide is located between the positive signal electrode and the negative signal electrode and used for bearing first optical signals, and the second optical waveguide is located between the first grounding electrode and the positive signal electrode or between the second grounding electrode and the negative signal electrode and used for bearing second optical signals. The carrier is used for bearing second optical signals. Constant-amplitude voltage signals with opposite phases are applied to the positive signal electrode and the negative signal electrode which are tightly coupled, so that the modulation efficiency can be improved, and the common-mode noise can be reduced.

An ultrasonic surgical instrument includes an end effector having an ultrasonic blade, an ultrasonic transducer assembly, and a shaft assembly. The shaft assembly includes a tube, and an waveguide. The waveguide is received within the tube and is acoustically connected between the ultrasonic blade and ultrasonic transducer assembly to communicate ultrasonic vibrations from the ultrasonic transducer assembly to the ultrasonic blade. The waveguide includes an acoustic body, a first isolation structure, a second isolation structure and a sheath. The acoustic body extends along a longitudinal axis. The first isolation structure radially extends about the acoustic body. The second isolation structure radially extends about the acoustic body and is longitudinally spaced from the first isolation structure. The sheath is radially positioned between the first isolation structure and the tube and is further radially positioned between the second isolation structure.

An apparatus includes a waveguide and one or more partially reflective surfaces embedded inside the waveguide, wherein each of the one or more partially reflective surfaces includes a multi-layer coating structure, wherein a first portion of the multi-layer coating structure induces an overall phase shift of light propagating through the first portion of the multi-layer coating structure and wherein a second portion of the multi-layer coating structure is selected to decrease the overall phase shift.

According to one embodiment, an antenna device includes a waveguide including a feed point and a first region. The first region is around the feed point on a first plane crossing a first axis direction passing through the feed point. The waveguide includes a plurality of radiating portions provided in the first region. Each of the radiating portions includes a first slot extending along a first slot direction and a second slot extending along a second slot direction crossing the first slot direction. The radiating portions include first and second radiating portions. A first radiating portion direction from the feed point to the first radiating portion crosses the first axis direction. A second radiating portion direction from the feed point to the second radiating portion crosses the first axis direction and crosses the first radiating portion direction.

The invention provides a bent waveguide structure, an electro-optical modulator and a light quantum computer, and relates to the technical field of electro-optical modulation.The bent waveguide structure comprises an input waveguide, a bent waveguide and an output waveguide which are sequentially connected, and the bent waveguide comprises a substrate transmission waveguide layer, an input coupling part and an output coupling part; the input coupling part and the output coupling part are arranged at the two ends of the substrate transmission waveguide layer respectively, a shallow etching groove is formed between the input coupling part and the output coupling part, the input coupling part is connected with the input waveguide, and the output coupling part is connected with the output waveguide. Compared with the prior art, the shallow etching groove is formed between the input coupling part and the output coupling part, so that the thickness of the waveguide film at the bending part is reduced to ensure that the substrate transmission waveguide layer is of a single-mode structure, the transmission loss is reduced, and the bending waveguide is relatively independent from the input waveguide and the output waveguide, so that the transmission efficiency is improved. Therefore, the process precision of the bent waveguide can be independently adjusted, the process time is reduced, and the efficiency is improved.

The invention belongs to the technical field of semiconductor devices, and particularly relates to an optical waveguide device based on a glass substrate, which comprises the glass substrate and a transition layer, an X silicon-based waveguide layer is arranged on the first surface of the transition layer, a heterogeneous material chip layer is integrated on the X silicon-based waveguide layer, the first surface of the X silicon-based waveguide layer is coated with a protective layer, and the protective layer is arranged on the first surface of the transition layer. The protective layer covers the glass substrate, the X silicon-based waveguide layer and the heterogeneous material chip layer at the same time; wherein the transition layer comprises an X element which is the same as that of the X silicon-based waveguide layer, through the above structure, the optical waveguide device with multiple layers of transition function areas is provided, the problems that the surface roughness of a large glass substrate is high, and the warping possibility is higher due to size effect amplification can be solved, and the optical waveguide device is suitable for large glass substrates. On the premise of fully utilizing the advantages of low cost and high performance of the glass substrate, the design of a large-size optical waveguide device for inhibiting packaging warping is realized.

A device includes a photonic routing structure including a silicon waveguide, photonic devices, and a grating coupler, wherein the silicon waveguide is optically coupled to the photonic devices and to the grating coupler; an interconnect structure on the photonic routing structure, wherein the grating coupler is configured to optically couple to an external optical fiber disposed over the interconnect structure; and computing sites on the interconnect structure, wherein each computing site includes an electronic die bonded to the interconnect structure, wherein each electronic die of the computing sites is electrically connected to a corresponding photonic device of the photonic devices.

The invention provides a patterned photonic crystal laser and a preparation method thereof, the laser comprises a substrate, and a first mask layer, a photonic crystal layer and a second mask layer which are sequentially deposited on the substrate, a light emitting area is etched in the central area of the second mask layer, and transparent conductive layers are deposited on the surface of the second mask layer and the light emitting area; a p-annular electrode is arranged on the surface of the transparent conductive layer on the second mask layer, and an n-annular electrode is arranged below the substrate; the photonic crystal layer is composed of a nanorod array and a polymer filled in gaps of nanorods; holes distributed in a patterned array are etched in the surface of the first mask layer, and nanorods are epitaxially grown in hole areas; the nanorod is formed by sequentially depositing a substrate contact layer, a first waveguide layer, a multi-quantum well layer, a second waveguide layer, a coating layer and a component gradient layer. According to the invention, through collaborative design optimization of all the layers, emission of laser with specific wavelength and preparation of a laser emitting laser with single longitudinal mode, narrow linewidth and stable wavelength are realized.

The invention provides a continuous depth gradually-changing grating structure based on a silicon carbide substrate and a preparation method thereof. The preparation method comprises the following steps: forming a sacrificial layer with gradually-changing thickness on the silicon carbide substrate; etching is carried out by adopting a two-step plasma etching process; and polishing the surface through a plasma polishing process. According to the invention, the gradient sacrificial layer is combined with two-step plasma etching, and a high-precision continuous depth gradient grating structure is realized on the silicon carbide substrate, so that the diffraction requirements of RGB three-color wavelengths are met; the micro-groove defect in the etching process is eliminated, the problem that the depth-to-width ratio and the surface quality cannot be considered in the traditional process is solved, and a key technical support is provided for mass production of the single-layer full-color optical waveguide; the transmission loss of the optical waveguide is reduced by controlling the surface roughness; and the product yield is improved, the production cost is reduced, and the method is suitable for large-scale production.

The invention discloses a low-power-consumption photonic integrated device preparation method and a corresponding device, and relates to the technical field of semiconductor optoelectronic integrated devices.The device comprises a substrate, a cantilever beam type grating layer, two gain layers, two modulator layers, a wrapping layer and an electric contact layer, the two gain layers and the two modulator layers are symmetrically distributed, and the wrapping layer and the electric contact layer form a shallow ridge waveguide structure. The two symmetrically-distributed gain layers and the middle cantilever beam type grating layer jointly form a double-end resonant cavity structure, the structure shares a unified grating and a thermal tuning platform to achieve continuous, synchronous and high-precision control over cavity mode wavelengths, and balanced modulation and phase synchronization of double-end output are achieved in cooperation with the symmetrically-integrated high-speed modulator layers on the two sides. According to the technical scheme, the gain layer, the grating layer and the modulator layer are symmetrically integrated on the same substrate, the alignment error of a multi-cavity structure is reduced, synchronous scanning, low drift and strong anti-interference high-quality laser output can be obtained, meanwhile, efficient thermal tuning is conducted through the cantilever beam type grating layer, and power consumption is remarkably reduced.

The invention relates to a calibration device (5) for calibrating radar-based level measuring devices (1) or their high-frequency module. For this purpose, the device (5) is based on a base body (51). A waveguide (52) runs within a planar plane (A) in this base body. The waveguide (52) is characterized by an input region (521), a coupling region for radar signals (S). HF , R HF ) reflective end region (522), and calibration section running between it (d kal ) out. According to the invention, the waveguide (52) or the calibration section (d) is kal ) are formed in a spirally nested configuration. This results in a spirally nested structure in relation to the length of the calibration section (d). kal ) or of the waveguide (52) achieves a very compact design, so that the calibration device (5) can also be used for recalibrations at the place of use of the level measuring device (1).

The invention discloses a low-divergence-angle narrow-linewidth high-power semiconductor laser. Relates to the technical field of semiconductor lasers, in particular to a low-divergence-angle narrow-linewidth high-power semiconductor laser. According to the invention, the parabolic waveguide structure is etched in the light field expansion area, and the metal reflector is introduced to realize a novel light field expansion and metal reflector integrated structure, and the transverse divergence angle of a laser mode is reduced through the expansion structure at the tail end of the waveguide. The laser comprises a laser gain area, a light field expansion area and a spectrum purification area at the tail of the light field expansion area. The laser gain region, the light field expansion region and the spectrum purification region at the tail part of the light field expansion region are made of the same laser epitaxial material in the longitudinal direction, the laser gain region is adjacent to the light field expansion region along the horizontal light emitting direction, and the light field expansion region is adjacent to the spectrum purification region at the tail part of the light field expansion region along the horizontal light emitting direction; the longitudinal direction is the direction from the substrate to the contact layer.

The invention relates to the technical field of chip preparation, and provides a chip based on an annular photonic crystal and a preparation method thereof. The preparation method comprises the following steps: growing a nucleating layer on a substrate; growing a superlattice structure on one side, away from the substrate, of the nucleating layer; sequentially growing an n-type coating layer, an n-type waveguide layer, a quantum well and a p-type electron blocking layer on one side, deviating from the nucleating layer, of the superlattice structure; etching a plurality of annular cavities on the p-type electron barrier layer to form an annular photonic crystal; growing a p-type extension contact layer on one side, deviating from the quantum well, of the p-type electron blocking layer; and carrying out in-situ annealing treatment. According to the preparation method, the directivity of the photonic band gap can be effectively adjusted, uniform light waves in all directions on the side face can be formed, so that leakage of laser from a non-light-emitting area on the side face is restrained, the light emitting efficiency is improved, the annular photonic crystals are periodically distributed, and the light beam quality is effectively guaranteed.

A chip-scale mode-locked laser including a cavity including a gain medium for amplifying signal electromagnetic radiation (signal) through stimulated emission, the signal comprising a signal wavelength; and a passive or active mode-locking device to enforce pulse formation in the laser. The mode-locking device includes a thin-film waveguide having a thickness on the order of the signal wavelength so as to confine and guide the signal along the thin-film waveguide, and a material comprising a second-order nonlinear susceptibility to enable active or passive mode-locking of the signal. The mode-locking device leads to generation of pulses of the signal outputted from the mode-locked laser.

The invention relates to an electro-optical modulator, a preparation method thereof and an electro-optical chip. The electro-optical modulator comprises a substrate, an optical beam splitter, a first optical waveguide, a second optical waveguide, traveling wave electrodes and an electro-optical film, the traveling wave electrodes comprise a first signal electrode and a second signal electrode, the first signal electrode and the second signal electrode are sequentially arranged in the second direction, the first signal electrode and the second signal electrode form a differential electrode, and the first signal electrode and the second signal electrode are sequentially arranged in the second direction. The first signal electrode generates a first electric field when transmitting a first electric signal, the second signal electrode generates a second electric field when transmitting a second electric signal, the directions of the first electric field and the second electric field are opposite, and the refractive index of the electro-optical film is changed under the action of the electric fields to realize electro-optical modulation; part of the electro-optical film, the first optical waveguide overlaps with the first electric field, and the other part of the electro-optical film overlaps with the second electric field. According to the invention, the differential driving of the electro-optical modulator is realized based on the electro-optical film, and the anti-interference capability and the transmission distance of the electro-optical modulator are effectively improved.

A hollow core fiber array unit includes hollow core fibers each having a terminal end and an adapter that includes grooves. Each groove receives the terminal end of one of the hollow core fibers. The terminal end of the hollow core fibers is spaced from an end face of the adapter. The hollow core fiber array unit includes a spot size converter coupled to the end face of the adapter. The spot size converter includes a plurality of waveguides that correspond to the hollow core fibers. Each waveguide extends from an input at an input end of the spot size converter that is coupled to the end face of the adapter to an output at an opposite output end of the spot size converter. The input of each waveguide includes a first mode field diameter that corresponds to the hollow core fibers and the output includes a second mode field diameter.

High-power, integrated optical amplifiers are described in which gain waveguides of the amplifiers are designed to improve power performance by reducing power saturation effects in the amplifier. The gain waveguides can change, in at least one aspect, along the length of the gain waveguide to reduce gain saturation. Multi-mode optical beams and / or multi-stage amplification can also be employed to reduce gain saturation.

The invention discloses a parallel simulation method for guided wave focusing imaging of a piezoelectric array of a composite structure, belongs to the technical field of nondestructive testing, and aims at solving the problems that the sound field control precision of a current multi-array-element piezoelectric structure in a composite material plate is insufficient, and a traditional finite element method is large in calculation time consumption, low in convergence speed and high in reliability in the guided wave propagation simulation process. In order to solve the problem that effective convergence cannot be realized under the excitation condition of a high-frequency multi-channel array and even under the excitation condition of a high-frequency multi-channel array, the invention provides an efficient guided wave focusing simulation strategy combining spectral element high-order precision and GPU parallel computing, and the method comprises the following steps: establishing a system control equation considering a piezoelectric-structure coupling effect on the basis of a delay superposition principle; energy focusing and sidelobe suppression of a guided wave signal in a specific direction are realized by adjusting spatial arrangement and excitation time sequence of a piezoelectric array sensor, Gauss-Labatto-Legendre integral nodes are introduced to construct a high-order spectral element unit, unit-level parallel solution is realized under a CUDA architecture, and dynamic simulation capability and overall calculation efficiency of focusing field distribution are remarkably improved.

Heterogeneous photonic circuits comprise a gain section optically coupled to a photonics section. The gain section can include at least one gain waveguide which can be formed from a III-V semiconductor material to provide optical gain. The gain waveguide can be coupled to optical components in the photonics section to form an integrated pump module. The photonics section can include a light-generating photonic circuit, which can comprise at least one waveguide doped with a rare-earth ion or transition-metal ion. Output from the integrated pump module and / or the light-generating photonic circuit can be tunable. Tuning can be implemented with feedback control.

The invention discloses a mouse spinal cord flexible electrode and a stimulation parameter optimization method, and relates to the technical field of parameter optimization. The mouse spinal cord flexible electrode comprises a soluble insertion layer, a gradient substrate layer, spinal cord anastomosis ribs, a conductive snakelike net, a hemispherical touch dot matrix, a microfluidic layer, an optical waveguide layer and a top packaging layer; the soluble insertion layer is photo-crosslinked PEG-DMA with the thickness of 5-25 m, the Young modulus is kept within the range of 0.8-1.5 GPa before implantation, and the soluble insertion layer is hydrolyzed in cerebrospinal fluid within 0.5-3 hours after implantation and completely falls off; the spinal cord anastomosis rib comprises an expandable S-shaped folding structure arranged on the upper surface of the gradient substrate layer, the distance between every two adjacent ribs ranges from 80 m to 200 m, the height of the folded state is not larger than 15 m, the height of the unfolded state ranges from 15 m to 40 m, and the spinal cord anastomosis rib is used for forming a cerebro-spinalfluid bypass groove extending in the longitudinal direction of the spinal cord on the surface of the dura mater. According to the invention, the positioning precision, safety and long-term efficiency of mouse spinal cord electrical stimulation can be effectively improved.

A dielectric waveguide structure of a semiconductor photonics device is formed prior to formation of the semiconductor photonics components of the semiconductor photonics device. This enables high-temperature processing techniques to be used to form the dielectric waveguide structure without concern for potential damage that might otherwise be caused to the semiconductor photonics components if the dielectric waveguide were to be formed above the semiconductor photonics components. The use of the high-temperature processing techniques may enable low optical loss to be achieved for the dielectric waveguide structure in that the high-temperature processing techniques may be used to achieve a low hydrogen concentration in the dielectric waveguide structure. The low hydrogen concentration in the dielectric waveguide structure enables higher performance to be achieved for the dielectric waveguide structure, including greater operating efficiency and increased communication bandwidth.

A first portion of incoming light and a second portion of incoming light travel in opposite directions within a first optical waveguide. A ring resonator in-couples the first portion of incoming light and the second portion of incoming light from the first optical waveguide, such that the first portion of incoming light and the second portion of incoming light travel in opposite directions within the ring resonator. A second optical waveguide is disposed to in-couple the first portion of incoming light and the second portion of incoming light couple from the ring resonator, such that the first portion of incoming light and the second portion of incoming light travel in opposite directions within the second optical waveguide away from the ring resonator. One or more photodetector(s) are optically connected to receive the first portion of incoming light and the second portion of incoming light from the second optical waveguide.

The invention discloses a high-isolation waveguide three-way power dividing and combining network structure which comprises a waveguide three-way power divider and a waveguide three-way power combiner, and an amplifier is connected between the waveguide three-way power divider and the waveguide three-way power combiner. The waveguide three-way power divider comprises a power divider upper waveguide cavity and a power divider lower waveguide cavity which are symmetrically arranged, and the power divider upper waveguide cavity and the power divider lower waveguide cavity are connected through screws. The waveguide three-path power combiner comprises a combiner upper waveguide cavity and a combiner lower waveguide cavity which are symmetrically arranged, and the combiner upper waveguide cavity and the combiner lower waveguide cavity are connected through screws. Microwave signals are distributed by the waveguide three-way power distributor, amplified by the amplifier, and then combined by the three-way power combiner. By constructing a brand-new three-path power division and synthesis network architecture, the problem of mutual load traction of amplifiers in a traditional non-isolated network is solved, and the stability of power synthesis is improved.

The invention relates to the technical field of optical waveguide master mask manufacturing processes, and discloses a monitoring and correcting method and system for an optical waveguide master mask etching process, and the method comprises the steps: setting a plurality of monitoring regions and corresponding monitoring point positions, and collecting the real-time monitoring data of each monitoring point position; inputting real-time monitoring data into the etching analysis model to obtain a real-time etching coefficient of each monitoring point; judging whether correction is needed or not according to the real-time corrosion coefficient, and if yes, determining a plurality of local defect areas and generating a correction instruction; a correction instruction is issued, a feedback time node is set, a correction data packet of each local defect area is collected according to the feedback time node, a correction evaluation value is generated, whether the local defect area is corrected again or not is judged according to the correction evaluation value, and real-time monitoring and accurate correction of the etching process are effectively achieved. The problems that in a traditional etching process, defects are known after being perceived due to lack of real-time monitoring, and resources are wasted due to global reworking are solved.

The invention provides a volume holographic grating exposure parameter determination method and a two-dimensional pupil expansion volume holographic optical waveguide, and the method comprises the steps: carrying out the multiple rotation of a vector of a first light beam, a vector of a second light beam and a holographic photosensitive material when the wavelengths of the first light beam and the second light beam are first recording wavelengths, the rotated vectors of the first light beam and the second light beam and the rotated material position of the holographic photosensitive material are obtained; converting the wavelengths of the first light beam and the second light beam into a second recording wavelength, and rotating the rotated vectors of the first light beam and the second light beam at least once to obtain in-material vectors of the first light beam and the second light beam; determining the in-air vectors of the first light beam and the second light beam according to the in-material vectors of the first light beam and the second light beam; and determining incident angles of the first light beam and the second light beam according to the in-air vectors of the first light beam and the second light beam. According to the method, the manufacturing efficiency of the two-dimensional pupil-expanding body holographic optical waveguide comprising the coupling-in, turning and coupling-out body holographic grating can be improved.

The invention relates to the technical field of semiconductor lasers, in particular to an ultra-narrow linewidth wavelength-adjustable external cavity laser based on a planar metal grating, which comprises a gain chip, and the left end face and the right end face of the gain chip are respectively plated with a high reflection film and a first antireflection film; a planar metal grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip is aligned and attached to the left end face of the planar metal grating waveguide, and a second antireflection film and a third antireflection film are plated on the left end face and the right end face of the planar metal grating waveguide respectively; the planar metal grating waveguide comprises a grating waveguide substrate, a ridge optical waveguide is arranged on the upper portion of the grating waveguide substrate, an annular resonance optical waveguide is arranged on the front side of the ridge optical waveguide, a planar metal grating is arranged on the upper portion of the ridge optical waveguide, and a top covering layer is arranged on the upper portion of the planar metal grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 700Hz and M2 less than 0.9 is realized.

The invention discloses an optical computing array based on micro-ring resonators without a free spectral range, which comprises an on-chip wavelength division multiplexing beam splitting array, an on-chip intensity modulation array, two groups of on-chip wavelength division multiplexing beam combining arrays and an on-chip balance detector, the on-chip wavelength division multiplexing beam splitting array and the on-chip wavelength division multiplexing beam combining array are respectively composed of a group of multiple FSR-free MRRs which share the same bus optical waveguide, each resonator corresponds to an independent wavelength channel, and the on-chip intensity modulator array is composed of a plurality of groups of on-chip MZI modulator arrays. According to the optical calculation array implementation method, independent control and coding calculation of different wavelength channels in a broadband wavelength range are realized by utilizing the single harmonic peak characteristic of the FSR-free MRR array and the wide-spectrum intensity modulation function of the MZI unit, the limitation of a free spectrum range on the optical calculation wavelength channel is eliminated, the higher wavelength parallelism is achieved, and the optical calculation array implementation method has the advantages of being simple in structure and convenient to implement. And therefore, the calculation scale is remarkably improved.

The present application relates to a kind of on-chip photo-thermal gas sensor and on-chip photo-thermal gas sensor assembly, the refractive index of the upper waveguide material layer of sensor ridge waveguide layer is greater than the refractive index of lower waveguide material layer, can support TM mode pump light and TE mode probe light simultaneously. That is, both high absorption of pump light and weak influence of probe light on the gas to be measured are considered, and the detection accuracy of the gas is improved. Moreover, a simpler waveguide structure is used, and the waveguide preparation process is simple, and the waveguide loss is relatively low. Compared with the photo-thermal interference method in optical fiber sensing, the interaction between pump light and the gas to be measured is greatly improved, the length of the detection waveguide is greatly shortened while ensuring high sensitivity, and the device size can be reduced to micrometer level. In addition, the waveguide structure of the on-chip photo-thermal gas sensor disclosed in the present application is prepared from chalcogenide glass, which has more obvious advantages for gas detection in the mid-infrared waveband.

The invention provides a semiconductor laser chip and a preparation method, and belongs to the technical field of semiconductor laser chip preparation, and the semiconductor laser chip comprises an N-surface metal, a substrate, an N-type limiting layer, an N-type waveguide layer, a tensile strain quantum well, a P-type waveguide layer, a P-type limiting layer, an ohmic contact layer, a SiO2 insulating layer, a first P-surface metal layer and a second P-surface metal layer which are sequentially arranged from bottom to top. Waveguide grooves are symmetrically formed in the two sides of the ohmic contact layer and penetrate through the ohmic contact layer, the bottoms of the grooves sink to the P-type limiting layer but do not exceed the P-type limiting layer, and a ridge waveguide is formed between the two grooves. The depth of the waveguide groove is of a stepped structure in the longitudinal direction, the depth of the area close to the cavity surface is increased to the N-type waveguide layer, the area completely covers the SiO2 insulating layer and the first layer of P-surface metal, but no second layer of P-surface metal exists, and the longitudinal stepped structure is formed. Through the design of the tensile strain quantum well and the stepped waveguide groove, cavity surface tensile strain release is realized, light absorption is reduced, and the reliability and the service life of the chip are improved.

The invention discloses a diffractive optical waveguide and a preparation method thereof, and a head-mounted display device, and relates to the technical field of augmented reality, and the preparation method of the diffractive optical waveguide comprises the steps: obtaining a target eye box range adaptive to a target crowd; according to the human eye parameters of each user group in the target group, splitting the target eye box range to obtain sub-eye box ranges adapted to each user group; diffractive optical waveguides adapted to the user groups are prepared based on the sub-eye box ranges, and the area of a coupled-out grating in each diffractive optical waveguide is smaller than the area of a coupled-out grating of an optical waveguide designed for covering the target eye box range. The optical efficiency and uniformity of the diffractive optical waveguide can be ensured, and the diffractive optical waveguide is prevented from generating obvious rainbow lines, so that the use experience of a user is improved.