229 results about "Blazed grating" patented technology

The invention discloses an external cavity tunable laser linewidth compression system for realizing wavelength phase locking based on mutual injection of gain chips. The external cavity tunable laser linewidth compression system comprises a red light semiconductor laser main gain chip, a first collimation optical system, a blazed grating, a tuning rotating mirror, a reflector, a power supply driving system and a double-path feedback amplification system, the double-path feedback amplification system comprises a first secondary gain chip, a second secondary gain chip, a second collimation optical system, a third collimation optical system and a polarization-free beam splitter prism; and the red light semiconductor laser main gain chip, the first secondary gain chip and the second secondary gain chip are all connected with the power supply driving system. Therefore, the technical problems of low output infrared light power, poor stability and narrow mode-hopping-free tuning range in the prior art are solved, and high-power, narrow-linewidth, high-stability and large-range mode-hopping-free continuous tuning red light output can be realized.

The invention relates to the field of optical detection, in particular to an interference confocal measurement system based on space coding and a measurement method thereof.White light generated by a light source is collimated through a first collimating lens and then divided into S polarized light and P polarized light through a polarization splitting prism, the S polarized light enters a reference plane mirror through a first quarter-wave plate, and the P polarized light enters a second quarter-wave plate; p polarized light enters a blazed grating through a second quarter-wave plate for transverse dispersion and then is changed into monochromatic polarized light with different wavelengths and the same focal length through a first achromatic lens, and the monochromatic polarized light and the monochromatic polarized light are jointly focused at the same depth position of an object to be measured. Information of the object to be measured is carried and returned to the polarization splitting prism, two beams of polarized light are combined and then focused on a target surface of a photoelectric detector of an imaging spectrometer with a mask plate through a focusing lens, an interference image of the object to be measured is obtained, and spectrum and interference analysis is carried out. According to the invention, the transverse scanning speed can be improved, the measurement time can be shortened, and the resolution can be improved.

The invention relates to a method for manufacturing a low-wavefront-error double-blazed grating for electron beam gray lithography, which comprises the following steps of: decomposing dose parameters of an electron beam into average dose and dose difference, decomposing grating parameters into grating height and grating depth, and constructing a mathematical model between the average dose and the dose difference; through differential calculation and least square fitting, the relation between the dose parameter and the height and depth of the grating is optimized, and then high-precision manufacturing of the target grating is achieved. The method comprises the following specific steps: firstly, decomposing dose and grating parameters, and establishing a first mathematical model among grating height, depth and dose parameters; and then obtaining relational data through an experiment, performing optimization calculation by using the second mathematical model, and finally obtaining a dose parameter corresponding to the target grating. And finally, manufacturing the double-blazed grating with the low wavefront error according to the target parameters. According to the method, wavefront errors can be effectively reduced, the photoetching precision is improved, and the method has relatively good manufacturing consistency and is suitable for the production requirements of high-precision gratings.

The invention belongs to the technical field of polarization imaging, and relates to a Sagnac broadband linear polarization imaging structure which comprises a second plane mirror, a first polarization beam splitter, a first polarization analyzer, a first imaging lens and a first focal plane array which are sequentially arranged on a first optical axis at intervals. The compensation plate is arranged close to the second plane mirror; the first plane mirror and the first polarization beam splitter are arranged on a second optical axis perpendicular to the first optical axis in a spaced mode and located on the side away from the compensation plate; the first blazed grating and the second blazed grating are reversely arranged at intervals and located on the light path between the first plane mirror and the second plane mirror, and the first blazed grating is close to the first plane mirror. The system provided by the invention is small in adjustment workload, high in accuracy, sufficient in shearing amount compensation, and good in broadband polarization imaging image precision and overall stability.

The invention provides a blazed grating manufacturing method, which comprises the following steps: providing a substrate, covering the substrate with periodically arranged masks, and etching the substrate by utilizing an incident angle and a rotation angle, taking the masks as a mask and utilizing an ion beam to form a blazed grating. The incident angle is the angle between the first projection of the ion beam on the plane where the normal of the substrate is located and the normal of the substrate, the rotation angle is the angle between the second projection of the ion beam on the plane where the surface of the substrate is located and the tangent line of the surface of the substrate, and the anti-blazing angle of the blazed grating is determined according to the incident angle and the rotation angle. Therefore, the shielding effect of the mask can be reduced by using the incident angle and the rotation angle, so that the purpose of controlling the angle of the anti-blazing angle is achieved, the angle of the anti-blazing angle is controllable, the angle of the anti-blazing angle is increased by controlling the incident angle and the rotation angle, and finally the diffraction efficiency of the blazed grating is improved.

The invention provides a femtosecond laser multi-focus parallel processing method, a femtosecond laser multi-focus parallel processing device and a fiber bragg grating inscribing method, which are characterized in that a plurality of blazed grating template holograms are superposed on a spatial light modulator, and a femtosecond laser beam is divided into a plurality of femtosecond laser beams with the same characteristics; and each beam of split light has information such as phase, diameter and the like which are the same as those of the femtosecond laser before beam splitting. After focusing through the objective lens, the focus of each beam of femtosecond laser on the focal plane also has the same size and focus depth as the original focus of the femtosecond laser. In addition, each beam of femtosecond laser is only acted by the corresponding blazed grating template, and the phase information of a certain beam of femtosecond laser can be independently adjusted by adjusting the corresponding blazed grating template, so that parameters such as the phase, the position and the form of the single certain beam of femtosecond laser are changed, and the accuracy of the femtosecond laser is improved. The micro-nano structure with a long uniform modification area in the femtosecond laser propagation direction is machined, multi-focus parallel machining is achieved, and the method can be applied to machining of fiber bragg gratings and the like.

A method for manufacturing a low-angle blazed grating on a semiconductor or silicon substrate, includes spin-coating the substrate with resist layer or hydrogen or polysilsesquioxane, being 100-1000 nm or few hundred nanometers thick, applying grayscale irradiation lithography exposure to the resist layer, generating a dose modulated pattern therein, varying in response to absorbed energy density from irradiation lithography exposure. The coated, irradiated substrate is developed in solution, such as TMAH or NaOH, enabling a blazed profile having structures of thickness-dependent diffusion barriers or SiO2, with 0-1000 nm height to emerge. Thermal oxidation in oxygen atmosphere at elevated temperature with the developed substrate, converts the upper silicon substrate layer into SiO2 to a depth depending on the thickness of the pattern in the resist layer above. Hydrofluoric acid fluid removes the SiO2, creating low-angle low-roughness blazed grating structure on silicon substrate.

An MEMS optical fiber surface-mounted strain gauge, configured to be fixed on the surface of an object to be measured to measure the strain of the object under a particular loading condition. The strain gauge is provided with a left side fixing part (1), a right side fixing part (2) and a quadrilateral structure (3) arranged between the left side fixing part (1) and the right side fixing part (2). The quadrilateral structure (3) is connected to the left side fixing part (1) and the right side fixing part (2) by means of diagonal connection parts, a collimator (41) is provided on a first edge (31) of the quadrilateral structure (3), a blazed grating (51) is provided on a second edge (32) of the quadrilateral structure (3), and the first edge (31) and the second edge (32) are two adjacent edges in the quadrilateral structure (3). The deformation of the quadrilateral structure (3) is monitored by means of the change of the angle between the adjacent edges.

The invention discloses a system and method for generating, regulating and controlling a partially coherent space-time light field. The system comprises a pulse shaping assembly composed of a plurality of optical elements and an incident light source used for providing a completely coherent ultrafast pulse light field. An optical element in the pulse shaping assembly comprises a first blazed grating, a first cylindrical lens, a two-dimensional dynamic holographic modulator, a second cylindrical lens and a second blazed grating which are sequentially arranged in the light field propagation direction. The focal lengths of the first cylindrical lens and the second cylindrical lens are the same, and the distance between the adjacent optical elements is equal to the focal lengths of the first cylindrical lens and the second cylindrical lens; the two-dimensional dynamic holographic modulator is used for loading a specific complex amplitude modulation function to reconstruct the spatial-spectral characteristics of the light field. According to the invention, the two-dimensional space-spectrum function of the pulse is dynamically modulated, the generation of the partially coherent space-time wave packet is realized, and the amplitude and structure distribution of the space-time coherence can be designed and regulated as required.

The invention provides a high-precision displacement measurement system based on a metasurface micro-lens array, and belongs to the field of micro-nano optics and high-precision measurement equipment. The system comprises two metasurface microlens arrays which are arranged in parallel, a collimation laser light source, a convex lens and an image sensor. The distance between the two metasurface micro-lens arrays is the sum of the focal lengths of the two metasurface micro-lens arrays, and is equivalent to a blazed grating of which the blazed angle is changed along with the relative displacement between the two metasurface micro-lenses; the intensities of adjacent diffraction orders on the two sides of a blazed angle of the blazed grating are highly sensitive to relative displacement, the convex lens projects a far-field diffraction angular spectrum of an emergent array beam to the image sensor, and the difference of the intensities of the adjacent diffraction orders on the two sides of the blazed angle is detected through the image sensor. Therefore, the relative displacement between the two metasurface microlens arrays can be obtained. The method is a displacement sensing technology which is high in sensitivity and rapid and does not need a complex post-processing algorithm, and is wide in application prospect.

The invention provides a compact high-power ultrashort pulse optical parametric amplification device. The compact high-power ultrashort pulse optical parametric amplification device is sequentially provided with a slide array, a first blazed grating pair, a slit, a first reflector and a second blazed grating pair in the direction of an optical path, the femtosecond laser is controlled to perform spectrum broadening through the ultrathin slide array, the grating is used for pulse width compression, and the adjustable slit is used for bandwidth selection, so that large-range continuous tuning of optical parameters such as wavelength, pulse width, power and the like of the ultrafast femtosecond laser is realized; the device is especially suitable for high-power hundred-femtosecond and sub-hundred-femtosecond lasers. According to the device, incident femtosecond laser can be efficiently converted, the pulse width and the spectral bandwidth can be greatly and continuously adjusted, and compared with the mode that spectrum broadening is achieved through high-pressure inert gas through femtosecond laser, the laser output stability is remarkably improved; the method is particularly suitable for light source parameter tuning in ultra-high time resolution spectrum testing and ultrafast laser processing systems.

The invention discloses a wavelength and repetition frequency independent adjustable gain-competition-free polarization-maintaining fiber common-cavity double-optical-comb mode-locked laser and an adjusting method, and relates to the technical field of optical frequency combs. In order to solve the problems that a system is easily influenced by an external environment, the anti-interference capability is poor and gain competition exists between optical combs due to the existence of a single-mode optical fiber in an existing optical fiber double-optical-comb structure, the invention provides an optical fiber double-optical-comb structure. According to the technical scheme, the laser comprises a polarization-maintaining pump laser, a first polarization-maintaining optical fiber coupler, a polarization-maintaining optical fiber wavelength division multiplexer, a polarization-maintaining ytterbium-doped optical fiber, a polarization-maintaining collimator and a blazed grating, laser output by a second polarization-maintaining optical fiber coupler is combined through a polarization-maintaining polarization beam combiner, and the polarization-maintaining polarization beam combiner serves as a horizontal polarizer and a vertical polarizer; the separated polarized laser is respectively coupled to a slow axis and a fast axis of a common-end tail fiber, and a semiconductor saturable absorber is used as a reflection end face. According to the invention, a full polarization-maintaining structure is adopted, the external environment resistance is strong, and the stability is greatly improved.

The present invention discloses a solid-state LiDAR device and a scanning method based on a tunable laser array. The array sequentially emits laser beams of different wavelengths, collimated by a collimating lens, and passes through a beam splitter. The beams are then diffracted by a blazed grating and focused by the first focusing lens onto the focal plane of the transmitting lens, and then emitted through the transmitting lens as collimated beams in different directions for wide area scanning. The optical receiving path uses the reversed coaxial system, where the received light returns to the beam splitter, redirects to the second focusing lens, and is finally focused on the detector. This invention incorporates tunable laser arrays, optical systems and dispersion devices to realize a solid-state wide-area scanning LiDAR device without moving parts, offering a wide scanning range, small size and fast scanning speed.

The invention provides a high-power external cavity tunable quantum cascade laser output module. The high-power external cavity tunable quantum cascade laser output module comprises a first lens, a first half-wave plate and a first mid-infrared grid polaroid which are sequentially arranged along a light path of a first laser; a second lens, a second half-wave plate, a second mid-infrared grid polarizer and a third half-wave plate are sequentially arranged along the light path of the second laser; emergent light of the first mid-infrared grid polaroid and the third half-wave plate is converged on different surfaces of the third mid-infrared grid polaroid, the first blazed grating is arranged on a reflection light path of the first mid-infrared grid polaroid, and the second blazed grating is arranged on a reflection light path of the second mid-infrared grid polaroid. According to the invention, the problems of wavelength locking and low polarization beam combination efficiency caused by insufficient polarization state of the quantum cascade laser can be effectively solved, narrow linewidth output and wavelength tuning of the quantum cascade laser can be realized, and even high-power dual-wavelength tunable output can be realized through polarization beam combination structure expansion.

The invention relates to a light leakage prevention diffraction optical waveguide which comprises a waveguide substrate, an input diffraction optical element and an output diffraction optical element. Incident light is coupled into the waveguide substrate through the input diffractive optical element, and is coupled out of the waveguide substrate step by step through the output diffractive optical element after being totally reflected in the waveguide substrate; the input diffractive optical element and the output diffractive optical element are respectively and independently arranged to be of a periodic grating structure, and a grating of the output diffractive optical element is arranged to be an asymmetric surface relief grating. The grating tilt direction of the output diffractive optical element and at least one further grating structure parameter are modulated such that the diffraction efficiency of the output diffractive optical element towards the out-coupling side exceeds the diffraction efficiency away from the out-coupling side, and the diffraction efficiency towards the out-coupling side varies spatially. According to the invention, the inclined grating or blazed grating easy to process is used in the coupling-out area, and the optical performance of the diffraction optical waveguide is considered by modulating the grating parameters, so that the effects of effectively weakening light leakage and ensuring the privacy of a user are achieved.

The invention is suitable for the field of electrochemical luminescence detection equipment, and provides a dispersion device suitable for electrochemical luminescence detection, which comprises a monochromator body, the monochromator body is composed of a monochromator housing, a reflector assembly, a grating assembly, a collimating mirror assembly, a focus lens assembly, a slit, a flange snap ring and a flange; an M-shaped light path is arranged in the monochromator body, and a slit, a reflector assembly, a collimating mirror M1 in the collimating mirror assembly, a customized blazed grating G1 in the grating assembly and a focusing mirror M2 in the focusing mirror assembly are sequentially arranged in the light propagation direction. The customized blazed grating G1 is designed by adopting specific parameters including the scribed line density, the blazed wavelength, the notch groove depth and the groove width ratio, and primary light energy enhancement and secondary light intensity suppression can be realized; according to the invention, an optical filter is not needed, the diffraction efficiency of a monochromator is improved to 60-86%, the intensity ratio of luminol secondary light to primary light is less than or equal to 1.6%, the detection limit of ruthenium bipyridine is reduced from 100pmol / L to 50pmol / L, and the electrochemical luminescence detection device is suitable for various electrochemical luminescence detection scenes.

The invention discloses a blazed grating manufacturing method, a blazed grating and a laser, the blazed grating manufacturing method comprises the steps that a substrate is etched to obtain a plurality of side walls and a plurality of grooves, the side walls extend in a first direction, the side walls are arranged at intervals in a second direction, the second direction is perpendicular to the first direction, and the grooves are formed in the first direction; a groove is arranged between any two adjacent side walls, and each side wall is provided with a first side surface and a second side surface which are arranged along a second direction. And filling the groove with a first photoresist. And configuring a third direction of the substrate to be parallel to the direction of the exposure light beam, and exposing the first photoresist, the third direction being a direction in which the top edge of the second side surface points to the bottom edge of the first side surface in the same groove. And developing the first photoresist to obtain a blazed surface. And etching each side wall to obtain a plurality of connecting surfaces. Through the mode, the blazed grating with any blazed angle and vertex angle can be obtained without customizing the monotectic orientation silicon substrate.

A super-resolution microscopic imaging method and apparatus based on common-path parallel fluorescence emission difference microscopy. In the method, a liquid crystal spatial light modulator is used to modulate excitation light in fluorescence emission difference microscopy super-resolution microscopic imaging, and two parts of the spatial light modulator are respectively loaded into 0-2π vortex phase modulation and blazed grating, so that the common-path excitation light forms solid spot and doughnut-shaped spot with a certain distance on a sample surface at the same time, and parallel scanning is carried out, thereby ensuring that the imaging speed is doubled compared with that of ordinary fluorescence emission difference super-resolution microscopic imaging, and at the same time, the two excitation lights are not easily affected by noise, drift and other interferences due to the common path.

The present invention provides a blazed grating and a method for fabricating the same. The method comprises: depositing a titanium dioxide optical film of uniform thickness on a target substrate; spin-coating an imprint adhesive onto the titanium dioxide optical film using a coating process; imprinting and patterning the imprint adhesive; selecting inductively coupled plasma etching parameters that match the target substrate for etching the titanium dioxide optical film; using the inductively coupled plasma etching parameters to etch the titanium dioxide optical film onto the target substrate to obtain a corresponding blazed grating; and transferring the nanoimprinted pattern using a corresponding inductively coupled plasma etching process based on the inductively coupled plasma etching parameters, thereby etching the titanium dioxide optical film onto the target substrate to obtain a corresponding blazed grating. Through process design and parameter optimization, the present invention fabricates a blazed grating with low roughness, high line density, good pattern fidelity, good blaze angle consistency, and high uniformity.

The invention provides a high-flux large-volume optical tomography system and method, and the system comprises a spatial light modulator which is used for carrying out the wavefront modulation of an incident laser beam, and generating an illumination light beam; a scanning device for generating an illumination light sheet based on the illumination beam; the sCMOS camera is used for detecting signals; the sample table is used for bearing and driving a sample to move; the synchronous control module is configured to control the spatial light modulator to dynamically load a composite phase pattern, and the composite phase pattern is formed by superposition of a depth-of-field phase component used for generating an extended depth-of-field light beam, a blazed grating phase component used for concentrating energy to first-level light and a lens phase component used for controlling a light beam focus to perform axial scanning; the synchronous control module is further configured to synchronously control the refreshing of the composite phase pattern and the deflection angle of the scanning device so as to acquire a three-dimensional image view field block through pure optical scanning during the stationary period of the sample stage. According to the invention, the imaging flux is greatly improved.

The present application provides a diffraction efficiency measurement device for an LCoS chip, which relates to the field of optical communication technologies. The device includes: a diffraction optical path module, a detection module, and a processing module; the diffraction optical path module is configured to reflect an input light source signal to a target LCoS chip according to a preset diffraction optical path, and the blazed gratings with different periods displayed on the target LCoS chip diffract the received light source signal to generate diffracted light corresponding to the blazed gratings with different periods; the detection module is configured to measure the optical signal intensity of the diffracted light corresponding to the blazed gratings with different periods, and send the optical signal intensity of the diffracted light corresponding to the blazed gratings with different periods to the processing module; the processing module is further configured to determine the diffraction efficiency of the target LCoS chip according to the optical signal intensity of the diffracted light corresponding to the blazed gratings with different periods, realizing the measurement of the optical signal intensity of the diffracted light corresponding to the blazed gratings with different periods displayed by the target LCoS chip at the same angle, and increasing the reliability of the test.

Diffraction gratings provide optical elements, e.g., in a head-mountable display system, that can affect light, for example by incoupling light into a waveguide, outcoupling light out of a waveguide, and / or multiplying light propagating in a waveguide. The diffraction gratings may be configured to have reduced polarization sensitivity such that light of different polarization states, or polarized and unpolarized light, is incoupled, outcoupled, multiplied, or otherwise affected with a similar level of efficiency. The reduced polarization sensitivity may be achieved through provision of a transmissive layer and a metallic layer on one or more gratings. A diffraction grating may comprise a blazed grating or other suitable configuration.

The invention relates to a blazed grating preparation method and a blazed grating. The preparation method of the blazed grating comprises the steps that a helical grating is prepared to obtain the helical grating, and the inclined surface of the helical grating is a blazed surface; depositing a cut-off material to the helical tooth grating to form a cut-off layer covering the blazing surface in the gap of the helical tooth grating to obtain a middle grating; grinding the middle grating to remove the redundant cut-off material, so that the upper end of the cut-off layer is flush with the upper end of the helical tooth grating; etching the ground middle grating to remove the helical tooth grating which is not protected by the cut-off layer to form an anti-blazing surface and an anti-blazing angle; and removing the cut-off layer to expose the blazed surface and form a blazed angle to obtain the blazed grating. According to the blazed grating preparation method, the blazed angle and the anti-blazed angle can be accurately controlled. According to the blazed grating preparation method, a flat blazed surface and a vertical anti-blazed angle can be formed, and the angle of the anti-blazed angle can be regulated and controlled.

A method is provided for forming optical elements with different optical element structures in a single element material layer. The method includes forming a patterned hard mask over an element material layer deposited on a top surface of a substrate, and patterning a first region of the element material layer to form a first plurality of optical features. The method also includes depositing a dielectric layer over the patterned hard mask, and selectively etching the dielectric layer and the element material layer to form a second plurality of optical features in a second region of the element material layer. The first plurality of optical features may be a binary grating structure, and the second plurality of optical features may be a blazed grating structure.

The present invention discloses a design method for a mask capable of rotating a light beam parallel to the optical axis. The present invention proposes a light beam that can be rotated parallel to the optical axis. By segmenting the shaped light beam and separately modulating additional Fourier phase shifts, and then superimposing them to obtain the hologram transmittance function of the light beam, combining the hologram transmittance function and a blazed grating, a mask capable of rotating a light beam parallel to the optical axis can be obtained. Using this mask, a light beam that can be rotated parallel to the optical axis can be generated. The rotation angle, beam size, and rotation radius of the light beam generated by this technology can all be arbitrarily modulated, thereby realizing longitudinal micro-manipulation of particles. This technology solves the problem that structured light beams cannot achieve longitudinal micro-manipulation of particles, and theoretically can endow structured light beams with the ability to support multi-particle longitudinal micro-manipulation in three-dimensional space. This technology is easy to operate and use, providing great potential for the future development of structured optical tweezers.

The present application relates to a kind of based on spectrometer imaging method and system of blaze grating.From the far field light of incident slit, into plano-convex lens, refract by plano-convex lens and meniscus lens, after again passing through thick catadioptric mirror concave surface reflection, with convergent light beam form is incident to convex blaze grating, after grating diffraction and reflection, form multiple beam single wavelength divergent light beam, in turn through thick catadioptric mirror reflection, meniscus lens and plano-convex lens refract, image on image plane, realize spectral imaging.The present application adopts immersion littrow-Offner structure, incident slit is off-axis in meridian and sagittal direction, so that incident slit and image plane are separated, facilitate engineering implementation;Spectrometer imaging system uses full immersion optical path, so that imaging spectrometer structure is more simple and compact, more convenient to assemble and use;Grating selects convex blaze grating, has high diffraction efficiency, so that the present imaging system can play a role in more extensive application field.

A design method of a Gibbs-Wulff optical vortex array mask plate, steps are as follows: obtaining an electric field expression of a Gibbs-Wulff optical vortex array, combining the amplitude, phase of the Gibbs-Wulff optical vortex array with a blazed grating, obtaining a complex transmittance function of the Gibbs-Wulff optical vortex array mask plate, and the mask plate described based on the complex transmittance function is the Gibbs-Wulff optical vortex array mask plate. The present application utilizes the principle of computer holography, and obtains the amplitude modulation phase mask plate of the Gibbs-Wulff optical vortex array through computer coding, so that the Gibbs-Wulff optical vortex array with controllable boundary and controllable structure and arrangement mode in the boundary can be generated. Thus, the present application has important application value in the fields of particle manipulation and optical micro-machining.

The present invention belongs to the field of micro-nano optics and beam shaping technology, and discloses a beam shaping method and system based on a metasurface blazed grating. The present invention places a first metasurface blazed grating and a second metasurface blazed grating in a shaping optical path; an asymmetric laser beam is incident on the first metasurface blazed grating along a first direction, and the first metasurface blazed grating is used to compress the beam along a second direction; the compressed beam is incident on the second metasurface blazed grating, and the second metasurface blazed grating is used to reorganize the beam along a third direction, shaping the beam after passing through the second metasurface blazed grating into an orthogonal symmetrical laser beam propagating along the first direction. The present invention uses the metasurface as a blazed grating to achieve beam shaping, and has a small size, light weight, and can be highly integrated, adapting to the development of miniaturization and micro-processing.

This application discloses an internal tilted blazed grating structure for optical glasses and its manufacturing method. The method includes forming a surface-modified photoresist pattern on a silicon carbide substrate; performing a first etching on the exposed surface of the substrate using the photoresist pattern to form a first trench with vertical sidewalls, filling it with a protective layer, and planarizing it; forming a triangular polysilicon pattern on the planarized substrate, and forming an oxide layer and a sidewall layer on its sides; using the polysilicon pattern with the sidewall layer as a mask to perform a second etching on the exposed surface of the substrate until the polysilicon pattern is completely etched away; and forming a second trench connected to the first trench and having a tilted sidewall on one side at the top of the first trench. This application reduces the complexity of the manufacturing process, facilitates the patterning of vertical and tilted sidewall structures, improves sidewall roughness, and is suitable for enhancing optical performance, increasing diffraction efficiency, and improving long-term stability.

The invention discloses two identification methods for a mark with a blazed grating structure on a substrate, and the method comprises the steps: carrying out the photoetching or etching of the blazed grating structure in the mark, carrying out the feature matching through recording the reflection efficiency in a wave band according to the characteristic that the blazed grating structure shines at a specific wavelength, and carrying out the recognition of the mark. The influence of interference factors such as falling dust and impurities on the substrate, photoresist spin coating defects and the like on mark grabbing can be effectively avoided. The accuracy of mark identification can be improved, the blazed grating structure has a unique diffraction efficiency characteristic, and under a specific blazed wavelength, the diffraction efficiency of the grating has a maximum value and forms an obvious difference with an interferent, so that the mark and the interferent can be accurately distinguished, and misjudgment of a visual positioning system is avoided.