24 results about "Apodization" patented technology

A switchable light modulating device with an electrophoretic medium disposed between a first light-transmissive electrode layer and a second electrode layer. The device includes one or more apodization structures in a bottom of a cell that contains the electrophoretic fluid, and the apodization structures reduce optical interference when the cell is in an open state and the structure is viewed with reflected or transmitted light passing through the apodization structure.

An imaging EUV optic (10) has a plurality of mirrors (M1 to M6) for guiding imaging light (16) along an imaging beam path from an object field (5) to an image field (11). The imaging optics (10) have a total apodization tilt APO Z3 that is less than 10%. A beam path intersection region (K1, K2, K3) lies between a first partial beam path (M1M2, M2M3) and a second partial beam path (M3M4, M4M5) in the imaging beam path. The first partial beam path (M1M2, M2M3) lies between a mirror (M1, M2) and a mirror (M2, M3) directly following this mirror in the imaging beam path. The second partial beam path (M3M4, M4M5) lies between another mirror (M3M4) and a mirror (M4M5) directly following this further mirror in the imaging beam path. An object-image offset (d) OIS) is greater than 250 mm. This results in an imaging EUV optic whose usability for an EUV projection exposure system is improved.

The application relates to a low-complexity adaptive beamforming method based on phase apodization cross-correlation, and belongs to the technical field of ultrasonic imaging. The method comprises the following steps: focusing and Hilbert transforming a sampling echo signal to obtain a complex echo signal; constructing multiple groups of amplitude apodization functions with different side lobe levels and peak response, weighting the echo signal, calculating and comparing the estimated variances of the apodized signals; constructing multiple groups of complementary phase apodization function pairs, phase apodizing the apodized signal with the minimum estimated variance, and calculating the real part similarity coefficient matrix of the phase-apodized signal pair; summing and averaging the multiple groups of thresholded similarity coefficient matrices and performing two-dimensional mean filtering; and multiplying the sum result of the apodized signal with the minimum variance estimation and the filtered similarity coefficient matrix to obtain the output of a beamformer and form an image. The application has the advantages of low calculation complexity, high robustness, etc., and can significantly improve the resolution and contrast of an ultrasonic image.

An apodization grating coupler based on a thin film lithium niobate platform comprises a silicon substrate, a buried silicon oxide layer, a thin film lithium niobate layer and a silicon oxide cladding which are sequentially arranged from bottom to top, and an end face coupler, a thin film lithium niobate waveguide, a light beam expander and an apodization grating are sequentially arranged in the thin film lithium niobate layer. The end face coupler couples light of the conical optical fiber into the thin film lithium niobate waveguide, and after the light is input into the apodization grating through the light beam expander, large-beam-waist Gaussian light beams are coupled through diffraction of the apodization grating. On the basis of the large-size apodization grating, through a compact plane photon structure, the 700 nm * 300 nm lithium niobate high-refractive-index single-mode waveguide can be coupled to a near-surface normal Gaussian beam with a beam waist of about 110 m and good collimation, the diffraction angle is 10 degrees, centimeter-level propagation is achieved in a free space, and the loss is 5.6 dB.

The invention belongs to the technical field of optical thin film detection, and particularly discloses an optimization method of an optical thin film detection system, which is used for solving the problems of weak interference resistance, poor pollution resistance and insufficient complex scene adaptation of the traditional detection system. The method comprises the following steps: pre-selecting a light needle beam with a needle-point-shaped cross section as a light source, defining a source plane light field, and constructing a limited energy generation condition through apodization operation; setting a plurality of groups of regulation and control parameters for three transmission states of diffraction, non-diffraction and focusing; building an experiment system to generate a directional light needle light beam, simulating pollution and interference scenes, and collecting light field data of different transmission nodes before and after interference; and quantizing the light field similarity through a witness function, screening an optimal regulation and control parameter, and integrating the optimal regulation and control parameter to a detection system. According to the invention, the anti-interference and information stability are improved from the light source essence, the method is adaptive to ultrathin, multi-layer thin film and complex environment detection, the detection precision and long-term stability are obviously improved, and both practicability and economy are taken into account.

A fitting method for an astigmatic contact lens set and an associated astigmatic contact lens set. The astigmatic contact lens set includes an apodization monooptic lens for lower lenticular error correction and a toric lens for higher lenticular error correction. An astigmatic eye having a lenticular error greater than a higher specified lenticular error label focal power (e.g., gt; 1.25 diopter (D)) may be equipped with a non-apodized toric lens with a stabilization mechanism. However, astigmatic eyes having lenticular errors up to higher specified lenticular error label powers (e.g., < = 1.25 diopters (D)) may be equipped with apodized monocular lenses. The apodized monocular lens has an apodized distribution that reduces aberration to provide improved vision, so that a larger number of astigmatic patients up to higher lenticular error can achieve acceptable vision with the apodized monocular lens and improve comfort due to the absence of a stabilizing mechanism.

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.

A variable light apodizer for apodizing a light beam is provided and includes at least one side filter disposed across a path of the light beam. Each side filter has a light transmission profile along an axis transverse to the propagation axis which is maximum from a first edge of the light beam up to a transition point within the light beam and gradually decreases from the transition point to a second edge of said light beam. The variable light apodizer further includes a filter-moving assembly having at least one mechanical mount one which are secured the side filters. Each mechanical mount is movable according to a motion shifting the light transmission profile of the side filter or filters thereon along the corresponding transverse axis. This motion provides a variable apodization of an edge portion of the light beam along the corresponding transverse axis.

An inspection system may be an EUV reticle inspection tool. The inspection system may include objective optics and imaging optics. The imaging optics may include pupil-relay optics. A first pupil-relay mirror of the pupil-relay optics may be extended into and retracted from the imaging path to enable imaging field images and pupil images on a detector. The pupil images may be used for measuring the intensity profile in pupil. Configurations of the pupil-relay optics may include the first pupil-relay mirror extending between a second and third objective mirrors of the objective optics or extending between fourth objective mirror of the objective optics and the detector.

The invention discloses an interdigital transducer and an elastic wave resonator, and belongs to the technical field of surface acoustic waves. The interdigital transducer comprises an interdigital transduction electrode structure, the interdigital transduction electrode structure comprises a first interdigital electrode and a second interdigital electrode which are oppositely arranged in the first direction, a plurality of finger strips in the first interdigital electrode and the second interdigital electrode are arranged in a staggered mode in the second direction to form an aperture area, and the first direction intersects with the second direction; the mass loads are formed on the interdigital transduction electrode structure and located in the aperture area, the mass loads are arranged to form at least one first curve and at least one second curve, the first curve and the second curve are located on the two sides of the center line of the interdigital transduction electrode structure, and the first curve and the second curve both meet a specific apodization function. According to the invention, an apodized mass load is arranged in an aperture area, a specific apodization curve is adopted, and a reflection boundary generating a transverse mode is destroyed, so that the transverse mode is inhibited, and the effective aperture size of the interdigital transduction electrode structure is not influenced.

An imaging EUV optical unit (10) has a plurality of mirrors (M1 to M6) for guiding imaging light (16) along an imaging beam path from an object field (5) to an image field (11). The imaging optical unit (10) has a total apodization tilt APO Z3 which is less than 10%. A beam path intersection region (K1, K2, K3) is present between a first partial beam path (M1M2, M2M3) and a second partial beam path (M3M4, M4M5) in the imaging beam path. The first partial beam path (M1M2, M2M3) lies between a mirror (M1, M2) and a mirror (M2, M3) directly following said mirror in the imaging beam path. The second partial beam path (M3M4, M4M5) lies between a further mirror (M3M4) and a mirror (M4M5) directly following said further mirror in the imaging beam path. An object image shift (dOIS) is greater than 250 mm. The result is an imaging EUV optical unit having improved usability for an EUV projection exposure apparatus.

The invention discloses an interdigital transducer and an elastic wave resonator, and belongs to the technical field of surface acoustic waves. The interdigital transducer comprises an interdigital transduction electrode structure, the interdigital transduction electrode structure comprises a first interdigital electrode and a second interdigital electrode which are oppositely arranged in the first direction and form an aperture area, the finger edge of the first interdigital electrode forms a first curve, and the finger edge of the second interdigital electrode forms a second curve; the mass loads are formed on the interdigital transduction electrode structure and located in the aperture area, and the mass loads are arranged to form at least one third curve and at least one fourth curve; wherein the first curve, the second curve, the third curve and the fourth curve all meet a specific apodization function. According to the interdigital transduction electrode, apodization is carried out on the edge of a finger strip in the interdigital transduction electrode structure, an apodization mass load is arranged in an aperture area, and a specific apodization curve is adopted, so that propagation of a transverse mode is blocked, the transverse mode is inhibited, and meanwhile, quality factors are not reduced.

The application discloses a nonlinear chirped fiber grating preparation method and system, and the method comprises the following steps: determining basic processing parameters of a fiber grating according to target parameters; based on the coupled mode theory, initially constructing a nonlinear periodic modulation function and a nonlinear apodization function, calculating a reflection spectrum and comparing the reflection spectrum with a target spectrum, and repeatedly adjusting the two functions for iteration optimization until the error reaches a standard; a periodic modulation selects a signal generator or a displacement table chirp, the former calculates a pulse delay according to a period value through a uniform displacement table, and the latter calculates a displacement table speed according to a period value through a uniform laser pulse; apodization modulation selects laser power or grating point spatial modulation, the former dynamically adjusts power to control the refractive index change, and the latter controls the laser focal point and the fiber core position; and the nonlinear chirped fiber grating is processed according to the optimized function and the selected mode. The application meets the application requirement of a complex optical system.

An apparatus is disclosed for a double-mode surface-acoustic-wave (SAW) filter with apodization. In example aspects, the apparatus includes a double-mode surface-acoustic-wave filter that includes multiple interdigital transducers having multiple fingers. An overlap region of fingers extending from opposite busbars establishes an aperture of the double-mode surface-acoustic-wave filter. The aperture forms an apodized structure across at least part of the double-mode surface-acoustic-wave filter. The multiple interdigital transducers include first and second interdigital transducers. The first interdigital transducer includes a first portion of the apodized structure. The second interdigital transducer includes a second portion of the apodized structure different from the first portion of the apodized structure of the first interdigital transducer. A transition region overlays a border between the first interdigital transducer and the second interdigital transducer. The transition region includes a transition portion of the apodized structure with the transition portion having a non-vanishing slope.

The application discloses a filter based on a multi-mode subwavelength grating. The filter comprises a mode demultiplexer for multiplexing and demultiplexing of a base mode and a high-order mode, a subwavelength grating for weakly binding regulation of a mode field of the base mode and the high-order mode, and a straight-through waveguide for output of the base mode. The application introduces a structure of the subwavelength grating and weakly binding regulation of the mode field, and by virtue of excellent flat dispersion regulation characteristics, the application realizes apodization of the grating while keeping consistent local refractive index of the grating, thereby obtaining the filter with high side mode suppression ratio and no free spectral range limitation, and the filter can realize flat and low-loss spectral response, meets the next-generation large-capacity and high-speed wavelength division multiplexing transmission demand, and has the advantages of simple structure, simple process, excellent performance and the like.

A method of making a grating coupler includes etching a first grating region into a substrate layer, wherein the first grating region comprises a first plurality of gratings having a first height and a first pitch between adjacent gratings of the first plurality of gratings. The method further includes etching a second grating region into the substrate layer, wherein the second grating region comprises a second plurality of gratings having a second height, different from the first height, and a second pitch between adjacent grating of the second plurality of gratings. The method further includes forming a cladding layer on the first and second grating regions, wherein the cladding layer has a different refractive index from the substrate layer.

The invention provides a multi-wavelength laser based on a rare earth doped integrated waveguide and a chirp Moire waveguide grating. Comprising a bidirectional pump laser unit, a wavelength division multiplexing coupler, a rare earth doped integrated waveguide with a chirp Moire waveguide grating, a broadband grating reflector and a rare earth doped waveguide power amplification unit. The broadband grating reflector, the rare earth doped integrated waveguide with the chirp Moire waveguide grating and the rare earth doped waveguide power amplification unit are connected in sequence, the chirp Moire waveguide grating on the rare earth doped waveguide is equivalent to a multipoint chirp phase shift grating subjected to cosine apodization, and the method is realized by adopting a forward design method or a reverse design method. The two-way pump laser adopts two-way pumping to input the rare earth doped integrated waveguide through the wavelength division multiplexing coupler, a laser resonant cavity is formed at each phase shift point of the chirp Moire waveguide grating, and single-frequency laser is generated. According to the invention, the stable equal-wavelength-interval multi-wavelength laser is realized by using the rare earth doped integrated waveguide with the chirp Moire waveguide grating.

The invention discloses a multi-receiving apodization super-resolution three-dimensional beam forming method and system, and the method comprises the steps: collecting a three-dimensional ultrafast ultrasonic echo RF signal, and carrying out the orthogonal demodulation, thereby obtaining a three-dimensional ultrafast ultrasonic echo signal; establishing a three-dimensional voxel grid; carrying out delay alignment according to a transmitting and receiving propagation path to obtain an aperture signal, carrying out row beam forming and column beam forming to obtain an aperture signal after row beam forming and an aperture signal after column beam forming, carrying out point multiplication operation with an apodization weighting function group, and carrying out envelope extraction to obtain three envelope signals; performing weighted summation on envelope signals obtained by the three apodization functions to construct a beam peak, and realizing super-resolution beam synthesis in the YZ direction and the XZ direction to obtain a super-resolution beam synthesis image; and carrying out Hadamard product operation to obtain a super-resolution beam forming three-dimensional image. According to the invention, the spatial resolution of three-dimensional ultrafast ultrasonic imaging can be improved, and the imaging quality of images is improved.

The present application relates to the technical field of fiber grating preparation, and particularly relates to a system and a method for automatically preparing a chirped fiber grating, the system comprising a laser, an electrically-controlled optical switch, an optical power attenuator, a dichroic mirror, a microscopic objective, and a three-dimensional displacement platform provided with a rotating clamp along an optical path; the system further comprises a control device electrically connected to the laser, the electrically-controlled optical switch, the optical power attenuator, and the three-dimensional displacement platform, respectively; and a CCD camera arranged on a side of the dichroic mirror away from the microscopic objective. The system is used to prepare the chirped fiber grating, and the system's optical pulse timing control and gray-scale lithography are realized through the cooperation of the system components, so that the fiber grating with different apodization modulation functions and chirp rates can be prepared at low cost and high efficiency; and the control of the laser, the electrically-controlled optical switch, the optical power attenuator, and the three-dimensional displacement platform by the controller improves the stability of the laser pulse output power and realizes the customized preparation of complex spectrum shapes.

The LiDAR receiver includes an optical element configured with a focal power to project light received at an input to a region where the received light overlaps. The apodized aperture in the region where the received rays overlap is configured with an optical transmission profile that varies radially across the apodized aperture to provide a desired modulation of the received overlapping rays. A detector optic positioned adjacent the apodization aperture focuses the modulated light on a detector plane. A two-dimensional pixelated detector array is positioned on a detector plane. The detector optics and the desired modulation are selected such that the ratio of the intensity of the modulated light on one pixel of the two-dimensional pixel array to the intensity of the modulated light on an adjacent pixel of the two-dimensional pixel array is a desired value.

The invention discloses a nonlinear chirped fiber grating preparation method and system. The method comprises the following steps: determining basic processing parameters of a fiber grating according to target parameters; based on a coupling mode theory, initially constructing a nonlinear periodic modulation function and a nonlinear apodization function, calculating a reflection spectrum and comparing the reflection spectrum with a target spectrum, and repeatedly adjusting the two functions for iterative optimization until an error reaches the standard; a signal generator or a displacement table chirp is selected for periodic modulation, the former calculates pulse delay according to a periodic value through a constant-speed displacement table, and the latter calculates the speed of the displacement table according to the periodic value through a uniform laser pulse; the apodization modulation selects laser power or grid point space modulation, the former dynamically adjusts the power to control the refractive index variation, and the latter controls the laser focus and the fiber core position; and processing according to an optimized function and a selected mode to form the nonlinear chirped fiber grating. And the application requirements of a complex optical system are met.

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.

Systems and methods are provided for suppressing the side-lobe artifacts in ultrasound imaging with plane wave compounding. The use of discrete angles in transmitting plane waves may be used to suppress side-lobes and the resulting side-lobe artifacts without increasing the number of firings required. A method is provided that utilizes nulls in Rx beam pattern to suppress side-lobes based on the beam pattern formula. An apodization technique that uses window functions according to Tx angles and / or Rx aperture may also be used. A method using aperiodic sampling angles may also be used to suppress artifacts. Application to arbitrary interval sampling angles may be found. Suppressing artifacts according to the present disclosure may provide for wider field of view imaging without resorting to increasing the number of firings required (NFR).