170 results about "Diffraction order" patented technology

The invention discloses a metasurface based on a nano resonator and a design method for realizing wavelength classification deflection. The metasurface is formed by periodically arranging three unit silicon nano resonators, wherein the widths of middle layers of the unit silicon nano resonators change in a gradient mode along the x axis, and the metasurface is of the sub-wavelength scale. The substrate of the unit resonator is a silver substrate, the surface of the silver substrate is provided with a silicon nanometer strip, and the top of the silicon nanometer strip and the top of the silver substrate are respectively deposited and covered with a layer of silver film; by adjusting the thickness of the middle silicon layer of the resonator, the working wavelength of a near-infrared band can be regulated and controlled, normal incident y polarized light with a specific wavelength is deflected to a diffraction order, light with other wavelengths is vertically reflected, and meanwhile, a phase modulation function is achieved. The device has the remarkable advantages of simple structure and convenience in preparation, has the advantages of high throughput and large-area preparation, and has important application prospects in new technologies such as optical imaging, spectrum detection and machine vision.

A programmable 3D light beam shaping device based on the beamlet printing technology comprises a laser source, the laser source emits initial laser, the polarization state of the initial laser is adjusted through a rotatable half-wave plate, and then the initial laser is separated into an s component light beam and a p component light beam through a first polarization splitting prism, the p-component light beam enters a Dammann grating after being expanded, and a diffracted light beam containing a plurality of diffraction orders is generated; the diffracted light beam sequentially passes through a second polarization splitting prism, a quarter-wave plate and a first focusing element and is introduced into focal shift by a multi-stage phase plate array, and the spatial light modulator is used for adjusting the angle and position offset of subgroups of the light beam of the sub-beam array to generate a working light beam; the working light beam returns to the second polarization splitting prism through the original light path and enters the working area through the second focusing element, and a three-dimensional light field is generated; according to the device, the three-dimensional irradiance distribution in a machining area can be accurately controlled, so that multi-layer and depth-adjustable energy deposition is realized, and the machining quality, efficiency and consistency are remarkably improved.

The application provides a laser processing brittle material multi-focus cracking device, which comprises a laser, a beam expanding and collimating system, a diffraction element and a beam focusing system; the laser is used for emitting laser; the beam expanding and collimating system is arranged on a light path of laser transmission, and is used for expanding the laser emitted by the laser; the diffraction element is used for making the laser generate multiple diffraction orders; and the beam focusing system is used for focusing the laser, so that the laser forms multiple focuses in the longitudinal position of the brittle material. The application controls the focusing sequence of the focuses in the material by introducing a specific diffraction optical element and adding a high-frequency oscillation filter on the focusing light path, and multiple modified layers are formed in the longitudinal position of the material through one-time scanning of the laser, so that the cold cracking efficiency is greatly improved.

The invention discloses a space customization three-dimensional column vector light beam array generation method based on a metasurface, and belongs to the field of micro-nano optics, diffraction optics and structured light field regulation and control. The implementation method comprises the following steps of: independently regulating and controlling left-hand circular polarization and right-hand circular polarization components of incident light based on geometric and propagation phase joint modulation of the metasurface; a metasurface, a phase distribution coding lens factor of a polarization channel, a Dammann vortex grating with opposite basic topological charges and a spiral Dammann zone plate are independently optimized, and left-handed and right-handed circular polarization components generate a three-dimensional vortex beam array with opposite spatial topological charges in a near-field Fresnel domain; the left-handed circular polarization vortex array and the right-handed circular polarization vortex array with opposite topological charges are coherently superposed to form a spatially customized three-dimensional column vector light beam array, and the vector characteristic of each light beam in the array depends on the amplitude ratio, the phase difference and the topological charges of the left-handed circular polarization component and the right-handed circular polarization component on each diffraction order. According to the invention, the regulation dimension of the column vector light beam can be expanded.

The invention discloses an optical chip, a spectrum sensing device and method, a spectrometer and equipment. The optical chip comprises an encoder with a non-periodic diffraction unit, and is used for enabling different light in a light beam to enter different diffraction units in the non-periodic diffraction unit for modulation so as to obtain optical signals in different diffraction directions. Therefore, spectral information corresponding to the light beam can be determined subsequently according to the light signal. In the application, different light in the light beam enters different diffraction units in the non-periodic diffraction units to be modulated to obtain light in different diffraction directions, and every two adjacent light signals in the light signals corresponding to the light are different in phase and phase difference, so that the space separation distance of different wavelengths is relatively large; and a relatively high resolution can be obtained. Meanwhile, along with the increase of the diffraction order, the light of each wavelength in different diffraction directions is not easy to overlap, so that the effective wavelength detection area is relatively large, and the bandwidth is relatively wide. Therefore, the problem of restriction between the resolution and the bandwidth is eliminated.

The polarization diffraction spectrometer comprises a substrate and a plurality of rectangular nano-columns arranged on the substrate, the rectangular nano-columns are periodically stacked or arranged in the height direction to form a periodic superlattice unit, and the substrate layer is made of a nanoscale transparent medium material; according to a grating equation, the optimal diffraction series, the period length and the incident light wavelength of the super grating are selected through experimental simulation, and optimal structural parameters are determined by combining an electromagnetic simulation tool and an optimization algorithm; the heights, the widths and the intervals of the rectangular nanocolumns serve as parameters of a particle swarm optimization algorithm, a fitness function with target diffraction order energy concentration ratio and target order overall diffraction efficiency optimization serving as core indexes is constructed, full-wave optical simulation software is combined, and geometric distribution in periodic units of the rectangular nanocolumns is optimized and adjusted. According to the invention, under the incident condition of 45-degree linearly polarized light, the S polarization component and the P polarization component are respectively concentrated at the preset target diffraction order, and an efficient diffraction light splitting effect is achieved.

An optical metrology system can include an overlay metrology tool for characterizing an overlay target on a sample, where the overlay target includes first direction periodic features in a first set of layers of the sample and second direction periodic features in a second set of layers of the sample. The overlay metrology tool can simultaneously illuminate the overlay target using first and second illumination beams and can further generate an image of the overlay target based on diffraction of the first and second illumination beams through the overlay target, where diffraction orders of the first illumination beam contribute to resolved image formation of only the first direction periodic features, and where diffraction orders of the second illumination beam contribute to resolved image formation of only the second direction periodic features. The system can further generate overlay measurements along first and second measurement directions based on the image.

A diffractive optical waveguide and a display device having the same are disclosed. The diffractive optical waveguide includes a grating structure formed on a surface of a waveguide substrate, the grating structure including a plurality of grating lines arranged in a plane, the grating lines each extending along a first direction in the plane and arranged at a predetermined interval in a second direction perpendicular to the first direction; at least one sidewall of each grating line having a periodic structure along the first direction; and the grating structure configured to diffract light incident thereon at a non-zero angle with respect to the plane out of the plane through a predetermined diffraction order. The grating structure employed in the above-described diffractive optical waveguide can be used to adjust the diffraction efficiency at different angles and / or different diffraction orders, thereby providing a new effective and flexible means for improving the angular uniformity and / or the out-coupling efficiency of the diffractive optical waveguide.

An optical alignment system including an illumination system configured to condition a radiation beam to form a first off-axis monopole, a marker configured to diffract the first off-axis monopole to form zeroth and first diffraction orders, a projection system configured to collect the zeroth and first diffraction orders and form an image of the marker, and a sensor apparatus configured to detect the image of the marker.

An eyewear device includes a lightguide having a world-side surface and an eye-side surface, a display oriented to emit light toward the lightguide, and a beam steering element that includes a first polarization grating positioned along an optical path between the display. The first polarization grating diffracts light emitted by the display into orders having different polarizations and the orders are selectively conveyed into different eyeboxes. The eyewear device also includes a frame that supports the lightguide, the display, and the first polarization grating. In some cases, the different polarizations include a right circular polarization or a left circular polarization and the beam steering element includes a polarization dependent filter that filters right circularly polarized light in a first state and left circularly polarized light in a second state.

A diffractive multifocal lens is disclosed, comprising an optical element having at least one diffractive surface, the surface profile comprising a plurality of annular concentric zones. The optical thickness of the surface profile changes monotonically with radius within each zone, while a distinct step in optical thickness at the junction between adjacent zones defines a step height. The step heights for respective zones may differ from one zone to another periodically so as to tailor diffraction order efficiencies of the optical element. In one example of a trifocal lens, step heights alternate between two values, the even-numbered step heights being lower than the odd-numbered step heights. By plotting a topographical representation of the diffraction efficiencies resulting from such a surface profile, step heights may be optimized to direct a desired level of light power into the diffraction orders corresponding to near, intermediate, and distance vision, thereby optimizing the lens performance.

The invention discloses a field-of-view expansion type sun sensor based on diffraction order multiplexing, which comprises a dual-band band-pass optical filter, a diffraction type light introducer and a color CMOS (Complementary Metal Oxide Semiconductor) image sensor, and is characterized in that the dual-band band-pass optical filter is used for selecting two pieces of separated sunlight with a preset wave band for incidence; the diffractive light introducer diffracts transmitted sunlight into multi-level light beams; the color CMOS image sensor is used for acquiring a diffraction spot image containing spectral information of two wave bands; the current effective diffraction order can be determined through the mass center positions of the light spots in the two corresponding wave band channels and the mapping relation between the light spot distance and the diffraction order, and finally the sun vector is obtained through calculation in combination with a diffraction optical model. According to the invention, the inherent contradiction that a large view field and high precision of a traditional digital sun sensor cannot be considered is solved, the problem of level ambiguity in a diffraction extended view field is effectively overcome, the lightweight design of the sun sensor adapts to the high-density integration requirement, and technical support is provided for spacecraft attitude measurement.

The invention provides a plasma photoetching imaging method and device and a computer readable medium, and the method comprises the steps: obtaining the axial direction of an imaging structure of plasma photoetching imaging, the imaging structure comprises a plurality of mask patterns which change periodically in one dimension, and irradiating the plurality of mask patterns in one-dimensional periodical change by light in a target direction forming a preset off-axis angle with the axial direction to obtain plasma photoetching images corresponding to the plurality of mask patterns in one-dimensional periodical change. That is to say, the diffraction order of the light can be influenced by irradiating the mask pattern in the target direction of the preset off-axis angle, so that the transmission efficiency of the light in the prohibited period range is improved, the contrast of the light intensity of the mask image in the prohibited period range during imaging is improved, and the imaging quality of the mask image in the prohibited period range is improved. And finally, realizing exposure imaging of the mask pattern in the prohibition period range.

A multi-focal ophthalmic lens using suppressed diffraction orders. A multi-focal ophthalmic lens includes an ophthalmic lens and a diffractive element. The ophthalmic lens has a base curvature corresponding to a base power. The diffractive element produces constructive interference in at least four consecutive diffraction orders corresponding to a range of vision between near vision and distance vision. The constructive interference produces a near focus point, a distance focus point, and an intermediate focus point between the near focus point and the distance focus point corresponding to the base power of the ophthalmic lens. The diffraction efficiency of at least one of the diffraction orders is suppressed to less than 10%.

The application provides a liquid crystal grating which can realize three diffraction modes by orthogonal orientation, comprising an upper glass substrate, an upper strip electrode I, an upper strip electrode II, a liquid crystal layer, a lower strip electrode I, a lower strip electrode II and a lower glass substrate. The diffraction mode of the liquid crystal grating is controlled by controlling the driving voltage V1 and V2 applied to the upper strip electrode I and the lower strip electrode I. When the driving voltage V1=0V and V2>0V, the incident light will be diffracted in the y direction through the liquid crystal layer. When the driving voltage V1>0V and V2=0V, the incident light will be diffracted in the x direction through the liquid crystal layer. When the driving voltage V1>0V and V2>0V, the incident light will be diffracted in the x and y directions through the liquid crystal layer. In addition, the diffraction order number and the diffraction efficiency of the liquid crystal grating can be adjusted by changing the size of the driving voltage V1 and V2.

Systems and methods for providing variable spot size and variable focus at a substrate are described. Sets of variable focal length lenses can be added to an alignment system to allow for adjustment of the spot size and focus. A variable focal length lens is a liquid lens that is tunable based on application of voltage across the lens. Toggling the voltage changes the water-oil interface in the liquid lens, which in turn changes the direction of light passing through. For example, turning on the voltage across the lens shifts the light output direction to converging at a focal point. As a result, variable focal length lenses provide adjustment to compensate for the fixed spot size and focus shortcomings of the prior art. Furthermore, variable focal length lenses can also be applied to compensate for spot shift and higher order diffraction orders.

This invention relates to the field of optical detection technology, specifically a multifocal parallel phase extraction and alignment system based on a spatial light modulator, comprising: a wavefront modulation module, a parallel detection module, an information extraction module, a parameter calculation module, and a correction and execution module. The wavefront modulation module loads a phase modulation pattern through a spatial light modulator, generating a complex wavefront containing multiple diffraction orders via the objective lens, forming multiple spatially separated detection focal spots on the sample surface. The parallel detection module receives the reflected light signals from each focal spot in parallel through an array detector. The information extraction module analyzes the signals and extracts the phase offset of each focal spot, constructing a mapping set between position and phase offset. The parameter calculation module calculates the tilt angle and field curvature distribution parameters based on this set. The correction and execution module generates a comprehensive correction signal to drive the objective lens or sample stage to perform multidimensional attitude adjustments. This system achieves multifocal parallel detection and synchronous parameter calculation, improving alignment efficiency and accuracy.

A position measurement encoder device includes a scale including a series of features readable by a read head to determine relative positions of the scale and the read head and diffract light into a plurality of diffraction orders; a readhead comprising a light source for illuminating the scale, and at least a first sensor configured to detect a signal generated at the first sensor by one or more diffraction orders generated by the scale; wherein the read head further comprises a diffraction order encoder that encodes the at least one diffraction order to have a different optical state than the optical state of the at least one other diffraction order.

The application provides an alignment device and an alignment method. The alignment device is provided with a first polarization adjustment unit, which comprises a first wave plate and a second wave plate connected in sequence. Positive and negative orders of diffraction with the same diffraction order in diffracted light or scattered light pass through the first wave plate and the second wave plate respectively. The direction of the fast axis of the first wave plate and the direction of the fast axis of the second wave plate form a first included angle, so that the diffracted light or scattered light with any polarization state can form a first light beam with a first polarization direction and a second light beam with a second polarization direction after passing through the first polarization adjustment unit, and the alignment measurement is realized independently of the polarization state. Based on this, the application also provides an alignment device. The alignment device simultaneously processes the fifth light beam and the sixth light beam by using a second polarization adjustment unit, eliminates the phase difference of each detection signal, and reduces the risk of modulation depth reduction.

Interferometric or holographic metrology systems may be used to determine overlay, alignment, and / or other metrics. Light scattered into different diffraction orders is detected by a first radiation sensor, together with two reference beams. The reference beams are carefully matched to two illumination paths from the two sources, such that a total interference pattern forms a hologram that encodes measurement information. Computational processing of the hologram determines metrology values. However, vibrations from metrology system stage settling and / or other sources cause path length shifts in the diffracted radiation. This negatively affects sensor performance. Advantageously, a second radiation sensor having a relatively higher frame rate is used to measure a phase shift from vibrations in near-real-time and make corrections for the vibrations.

The invention provides an optical system, a three-dimensional information acquisition method and a three-dimensional reconstruction method.The optical system comprises a super-structure grating, a focusing lens and an imaging detector which are sequentially arranged along an optical axis, and the super-structure grating splits reflected light beams of a target object on at least four different diffraction levels to obtain at least four polarization sensitive light beams; the focusing lens is used for focusing the light beams split by the super-structure grating to different imaging areas of the imaging detector to form a plurality of sub-images, and the plurality of sub-images comprise polarization sub-images in one-to-one correspondence with the at least four polarization sensitive light beams; the image processing module is in communication connection with the imaging detector, and the image processing module calculates the depth information of the target object according to the parallax of the at least two sub-images and calculates the polarization information of the reflected light beam according to the at least four polarization sub-images; depth information and polarization information can be obtained through single shooting, and the optical system is simple and compact in size.

The application discloses a design method and system of a polarization detection metasurface. The method comprises the following steps: establishing a microstructure model, scanning the phase delay of microstructures with different geometric sizes under x and y polarizations; specifying two groups of orthogonal polarization states and target propagation angles, calculating the supercell size and the number of microstructures contained therein, and confirming the polarization beam splitting target required under the two groups of orthogonal polarization states; calculating the Jones matrix of each microstructure in the supercell and selecting a group of microstructure parameters as the initial solution; establishing a supercell model according to the initial solution and performing forward propagation simulation to obtain the diffraction order intensity distribution under the two groups of orthogonal polarizations, and constructing a loss function to obtain the optimal supercell structure meeting the polarization beam splitting target after iterative optimization; and performing two-dimensional periodic expansion on the supercell structure to obtain a metasurface structure. The application can realize efficient separation of multiple polarization states on a single metasurface, avoids the crosstalk problem in the traditional space division multiplexing mode, and improves the spatial resolution.

The invention provides a photoetching device preparation method for inhibiting a mask three-dimensional effect. The photoetching device preparation method can be applied to the technical field of integrated circuit manufacturing and photoetching. The preparation method of the photoetching device for inhibiting the three-dimensional effect of the mask comprises the steps that a plurality of candidate metal-medium multilayer film structures are constructed based on preset configuration parameters, and metal layer materials in different candidate metal-medium multilayer film structures are different; acquiring optical transfer functions corresponding to the plurality of candidate metal-medium multilayer film structures; screening out a target metal-medium multilayer film structure supporting a single high-order diffraction order dominant imaging mode from the plurality of candidate metal-medium multilayer film structures according to response characteristics of each optical transfer function in a spatial frequency domain; and preparing the photoetching device based on the target metal-medium multilayer film structure. The invention also provides a photoetching device for inhibiting the three-dimensional effect of the mask.

In a first aspect, the invention relates to an optical arrangement (1, 12) for a diffractive display. Said display has, in sequence along a direction of extent, a first reflective diffraction grating (15), a polarisation modulator (16), a second reflective diffraction grating (17) and a polarisation filter (18) for the first polarisation, the second polarisation being a transmission polarisation. The polarisation modulator (16) is configured to convert, at least in part, a portion of light having a first linear polarisation and a portion of light having a second polarisation, perpendicular to the first polarisation, into one another, the portions depending on the angle of incidence of the light on the polarisation modulator (16). The second reflective diffraction grating (17) is configured to diffract light with a first angle of incidence on the diffraction grating at least partially in the direction of the first reflective diffraction grating (15) with a first angle of emergence, and the first reflective diffraction grating (15) is configured to diffract diffracted light from the second reflective diffraction grating (17) at least partially with a second angle of emergence in the direction of the polarisation filter (18). The portion of the light which is converted by the polarisation modulator (16) from the first polarisation to the second polarisation or, conversely, from the second polarisation to the first polarisation is not the same for the second angle of emergence as for the first angle of emergence. Further aspects of the invention relate to a display device having the optical arrangement.

Disclosed is a method of determining an illumination-detection system alignment of an illumination-detection system describing alignment of at least one detector and / or measurement illumination of a metrology apparatus in terms of two or more illumination-detection system alignment parameters, each illumination-detection system alignment parameter relating to a respective degree of freedom for aligning the detector and / or the measurement illumination. The method comprises obtaining a diffraction pattern relating to diffraction of broadband radiation from a structure; transforming each of one or more diffraction orders of the diffraction pattern to a respective region coordinate system, each region coordinate system comprising a first axis and a second axis, each region coordinate system being such that said first axis is aligned in relation to a direction of an intensity metric of each transformed diffraction order; and determining illumination-detection system alignment parameter values for the illumination-detection system alignment parameters.

A programmable 3D beam shaping device based on beamlet printing technology, comprising a laser source, the laser source emits initial laser, the initial laser adjusts the polarization state through a rotatable half-wave plate, and then is separated into orthogonal s component beam and p component beam through a first polarization beam splitter prism; the p component beam is expanded and then enters a Dammann grating to generate a diffraction beam containing several diffraction orders; the diffraction beam passes through a second polarization beam splitter prism, a quarter-wave plate and a first focusing element in turn, introduces focal shift by a multi-stage phase plate array, adjusts the angle and position offset of the sub-group of the sub-beam array beam by a spatial light modulator to generate a working beam, the working beam returns to the second polarization beam splitter prism from the original light path and is emitted into a working area by a second focusing element, generating a three-dimensional light field; the device can accurately control the three-dimensional irradiance distribution in the processing area, thereby realizing multi-level and depth-adjustable energy deposition, and significantly improving the quality, efficiency and consistency of processing.

The invention discloses a design method and system of a polarization detection metasurface. The method comprises the following steps: establishing a microstructure model, and scanning phase delays of microstructures with different geometric dimensions under x and y polarization; specifying two groups of cross-polarization states and target propagation angles thereof, calculating the size of a super-unit cell and the number of microstructures contained in the super-unit cell, and confirming polarization beam splitting targets required in the two groups of cross-polarization states; calculating a Jones matrix of each microstructure in the supercell and selecting a group of microstructure parameters as an initial solution; establishing a super-cell model according to the initial solution and performing forward propagation simulation to obtain diffraction order intensity distribution under two groups of orthogonal polarization, and constructing a loss function to perform iterative optimization to obtain an optimal super-cell structure meeting a polarization beam splitting target; and carrying out two-dimensional periodic expansion on the super-unit cell structure to obtain the super-surface structure. According to the invention, efficient separation of multiple polarization states can be realized on a single metasurface, the crosstalk problem in a traditional space division multiplexing mode is avoided, and the spatial resolution is improved.

The application provides an optical waveguide and an electronic device. The optical waveguide comprises a waveguide substrate, and a coupling-in region and a coupling-out region are arranged on the side surface of the waveguide substrate. The coupling-in region is used for coupling light into the waveguide substrate, and the light is coupled out from the coupling-out region after reflection propagation inside the waveguide substrate. One of the coupling-in region and the coupling-out region is a positive dispersion region, and the other is a negative dispersion region. The dispersion generated after the light passes through the positive dispersion region is used for compensating the dispersion generated after the light passes through the negative dispersion region. The processing effects of the positive dispersion region and the negative dispersion region on light of different wavelengths can be mutually compensated, so that light of different wavelengths incident at the same incident angle can be emitted at a similar refraction angle. In this way, the light of different wavelengths can have a similar diffraction order when being coupled out, the energy of the light of different wavelengths coupled out is similar, and thus the picture effect of the electronic device is improved.

Example embodiments provide methods, systems, apparatuses, computer program products and / or the like for reducing diffractive orders arising from metasurface optics. In various embodiments, reducing diffractive orders is achieved by intentional apodization of emergent superstructures and / or intentional amplitude apodization of metasurface apertures. For example, various embodiments provide methods for designing and / or fabricating metasurfaces using a metastructure library that includes parameters defining a plurality of metastructures indexed by respective effective phase delays imparted to light that interacts with the corresponding metastructures. For at least one effective phase delay, the metastructure library comprises parameters that define at least two metastructures that differ in at least one of size or shape and that are indexed by the same effective phase delay.