Abstract: There is provided a new apparatus, system, and method of use for laser speckle imaging that allows for omni-directional viewing. The omni-directional viewing can include a reflector and switches configured for switching the illumination on the luminal tissue such that the light reflected from the luminal tissue at any given time is reflected from one or more substantially non-overlapping sections of a luminal tissue. This apparatus may be particularly useful for tissue analysis such as analysis of vulnerable plaque.

Abstract: The present disclosure relates to an apparatus for non-invasively estimating a target component value based on a light spectrum. The apparatus for estimating the target component value may include a sensor configured to obtain a spectrum of light scattered or reflected from an object, and a processor configured to correct a first reflectance value of the spectrum based on a melanin index; obtain a second reflectance value based on correcting the first reflectance value; convert the second reflectance value into an absorbance value; estimate the target component value based on the absorbance value; and correct the target component value based on a hemoglobin index.

Abstract: An environment sensing method includes the following steps, carried out by a data processor a) defining an occupancy grid comprising a plurality of cells; b) acquiring at least one measurement result from a distance sensor, representative of the distance of one or more nearest targets; and c) computing an occupation probability of the cells of the occupancy grid by applying to the measurement an inverse sensor model stored in a memory device in the form of a data structure representing a plurality of model grids associated to respective distance measurement results, at least some cells of a model grid corresponding to a plurality of contiguous cells of the occupancy grid belonging to a same of a plurality of angular sectors into which the field of view of the distance sensor is divided, and associating a same occupation probability to each one of the plurality of cells.

Abstract: A divided-aperture infrared spectral imaging (DAISI) system that is structured to provide identification of target chemical content in a single imaging shot based on spectrally-multiplexed operation. The system is devoid of spectral scanning acquisition of infrared (IR) spectral signatures of target content with an IR detector and does not require content.

Abstract: Methods for evaluating sensor data to predict when the sensor should be recalibrated are described. The methods include a model that utilizes current wellbore data as input for the recalibration prediction.

Abstract: Provided is a method for monitoring a manufacturing process of an agricultural product. The method utilizes hyperspectral imaging and comprises scanning at least one region along a sample of agricultural product using at least one light source of a single or different wavelengths; generating hyperspectral images from the at least one region; determining a spectral fingerprint for the sample of agricultural product from the hyperspectral images; and comparing the spectral fingerprint so obtained to a spectral fingerprint database containing a plurality of fingerprints obtained at various points of the manufacturing process, using a computer processor, to determine which point in the manufacturing process the sample has progressed to.

Abstract: A device for holding and testing plant material includes a sample container including a sample fixation member for affixing thereto a plant sample such that the plant sample is held vertically in the sample container, a test and calibration reference, a spectrometer arranged to perform spectrometric analysis of the plant sample with respect to spectrometric analysis of the test and calibration reference, and a multiple-degree-of-freedom positioning device configured to cause relative movement between the sample container and the spectrometer.

Abstract: A spectroscopic module includes a plurality of beam splitters that are arranged along an X direction; a plurality of bandpass filters disposed on one side in a Z direction with respect to the plurality of beam splitters facing the plurality of beam splitters, respectively; a light detector disposed on the one side in the Z direction with respect to the plurality of bandpass filters and including a plurality of light receiving regions facing the plurality of bandpass filters, respectively; a first support body supporting the plurality of beam splitters; and a second support body supporting the plurality of bandpass filters. The second support body includes a support portion in which a support surface is formed so as to be open to the one side in the Z direction. The plurality of bandpass filters are disposed on the support surface.

Abstract: An inspection device includes: an irradiator that irradiates an object with near-infrared light; a spectroscope that disperses reflected light from the irradiated object; an imaging device that takes a spectroscopic image of the reflected light; a processor that: obtains spectral data of a plurality of points on the object, based on the spectroscopic image; defines a group of similar spectral data from among the spectral data of the plurality of points; extracts a group having a largest number of spectral data from the defined group; calculates an average of the spectral data of the extracted group; and detects a type of the object using a predetermined analysis of the object, based on the average.

Abstract: A movable diffraction element and a spectroscope. The movable diffraction element includes a movable component having a comb-like shape, a supporting unit configured to support the movable component, a first cantilever actuator coupled to the supporting unit, a displacement determiner coupled to an edge of the first cantilever actuator, and a second cantilever actuator disposed parallel to the first cantilever actuator. In the movable diffraction element, a slope generated when the second cantilever actuator deforms is approximately equivalent to a slope generated at the first cantilever actuator. The spectroscope includes the movable diffraction element.

Abstract: A system and method for automated grain inspection and analysis of results during harvest, using an inspection system mounted on a combine harvester with geolocation tracking, allowing for real time analysis during harvest and tracking of grain quality by location of harvest.

Abstract: Method and gas analyzer for measuring the concentration of a gas component in a measurement gas, a wavelength-tunable laser diode is actuated with a current, one part of the light generated by the laser diode is guided through the measurement gas to a measuring detector to generate a measuring signal, the other part of the light is guided to a monitor detector to generate a monitor signal, the current is varied in periodically consecutive scanning intervals to scan an absorption line of interest of the gas component as a function of the wavelength, the current is further modulated with a radio-frequency noise signal having a lower cut-off frequency selected as a function of the properties of the laser diode and high enough to ensure no wavelength modulation occurs and the measuring signal is correlated with the monitor signal and then evaluated to generate a measurement result.

Abstract: Described herein are a spectrometer system and a spectrometer device, which are suited for investigation or monitoring purposes, in particular, in the infrared (IR) spectral region, and for a detection of heat, flames, fire, or smoke. The spectrometer device allows capturing incident light from object and transferring the incident light to a length variable filter with a particularly high concentration efficiency. Apart from the spectrometer device, the spectrometer system further includes an evaluation unit designated for determining information related to a spectrum of an object by evaluating the detector signals provided by the spectrometer device.

Abstract: The present disclosure relates to mobile devices for analyzing a chemical composition, and related methods of analyzing a chemical composition. A benefit of embodiments disclosed herein can include portable and economical devices providing for simple and rapid analysis of luminescent chemical sensor arrays. A benefit of methods disclosed herein can include the use of embodied devices to provide highly accurate qualitative and quantitative analyses of the components of a broad range of chemical compositions. A benefit of the methods disclosed herein can include the rapid, simple, and accurate analysis of trace chemicals present in chemical compositions.

Abstract: A sample-container holding member is detachably attached to an integrator via a fixing member and holds a sample container, which comprises a cell containing a sample and a cap, in a state where the sample container is placed in the integrator. The sample-container holding member comprises a pillar-shaped support portion fixed to the fixing member and a container attaching portion which is provided at an end of the support portion in the axial direction and to which the sample container is attached. The container attaching portion comprises a housing portion housing a cap and a holding portion having contact with at least three points on an outer surface of the cell and holding the sample container.

Abstract: In a spectrometry setup where a first spectral component dominates a second spectral component having a different wavelength, diffraction of the first spectral component as it passes through the optical train of the spectrometer can produce spectral noise that obscures detection of the second spectral component. To reduce the spectral noise, the light from the spectrometer is subject to spatial filtering or interference such that effects of the first spectral component are removed, or at least reduced. The second spectral component can then be more readily detected by a detector after the spatial filtering or interference. In embodiments, the spatial filtering or interference may be provided by a filtering module, which may be installed in existing spectrometry setups or form part of a unitary spectrometry system.

Abstract: A gain switched dual comb spectroscopy device for spectroscopically detecting a sample substance, comprising a first slave laser light source configured to generate a first frequency comb having a first comb free spectral range, and a second slave laser light source configured to generate a second frequency comb having a second comb free spectral range which is different from the first comb free spectral range. A master laser light source is configured to inject seed light in to both slave laser light sources therewith to injection lock the generation of both the first and the second frequency combs. A photodetector part is arranged to combine the first and the second frequency combs and to detect a beat signal the spectrum of which comprises a third frequency comb including beat tones produced by interference between the combined first and second frequency combs.

Abstract: A birefringent spectral demultiplexer for hyperspectral imaging includes N birefringent beamsplitting stages arranged along a light propagation path, to produce 2N mutually divergent output light beams. Each of the output light beams differs from every other one of the output light beams in polarization and/or spectral bandwidth. Each birefringent beamsplitting stage includes a retarder for modifying polarization of each light beam received by the birefringent beamsplitting stage, and a Wollaston prism for splitting each light beam into two orthogonally polarized and divergent light beams. The Wollaston prism has a beamsplitting interface arranged at an oblique angle to the light propagation path. The oblique angle of the beamsplitting interface of each Wollaston prism of the series, except for the first one, is smaller than the oblique angle of the beamsplitting interface of each preceding Wollaston prism. The demultiplexer may be configured to accept input light of any polarization.

Abstract: An optical emission spectroscopy system may include a reference light source, an analyzer to receive and analyze light transmitted from the reference light source, and a calibrator to calibrate light emitted from the reference light source. The calibrator may change a calibration ratio in accordance with an incidence angle of the light.

Abstract: Compact spectrometer modules include an illumination channel and a detection channel. The illumination channel includes an illumination source operable to generate a broad spectrum of electromagnetic radiation. The detection channel includes an illumination detector and a Fabry-Perot component. The Fabry-Perot component is operable to pass a narrow spectrum of wavelengths to the illumination detector. Further, the Fabry-Perot component can be actuatable such that the Fabry-Perot component is operable to pass a plurality of narrow spectrums of wavelengths to the illumination detector.

Abstract: A method, a device, and a non-transitory storage medium provide a location-based remote testing service. The location-based remote testing service may receive a request for a remote test that includes location information indicating a location subject to a remote test. The service may correlate the location information to a network element of a network. The service may perform a remote test on the network element. The service may provide a result of the remote test to a device that requests the remote test.

Abstract: A spectrometer is provided which comprises a Virtually Imaged Phased Array member configured to receive an electromagnetic input radiation and to generate an electromagnetic output radiation, in which a spectrum of the electromagnetic output radiation is dispersed along a dispersion axis (x) transverse to an optical axis (z) of propagation of the electromagnetic output radiation; a Fourier lens adapted to convert the output electromagnetic radiation into a spectral pattern; an image sensor adapted to detect the spectral pattern; and at least one diffraction mask arranged along the optical axis (z) for propagating the output electromagnetic radiation, in a position not coincident with a spectral plane of the spectrometer. Through the diffraction mask, which comprises a material blocking the transmission of the output electromagnetic radiation, an aperture is obtained which allows the transmission of the output electromagnetic radiation, and whose edge comprises at least one inclined segment.

Abstract: An inspection device has an illuminating optical system for forming an illuminated area on a sample, a converging optical system for converging the light from the sample, and a detector for detecting the light converged by the converging optical system. The converging optical system includes an image forming element that includes a lens group that has divided apertures and is configured so as to form a plurality of images. The detector detects a signal for the images formed by the image forming element. The detector has a plurality of partitions disposed in a matrix, the partitions include first and second pixels, and the images are projected onto the partitions.

Abstract: A cutting device for a thin semiconductor wafer includes a laser light generator and a polygonal mirror structure. The laser light generator is used to provide a femtosecond laser light with a pulse width on a femtosecond order (10?15 second). The polygonal mirror structure is used to reflect the femtosecond laser light. The polygonal mirror structure has a plurality of reflective surfaces. The polygonal mirror structure rotates continuously with respect to the femtosecond laser light, such that the femtosecond laser light is sequentially and repeatedly reflected by the plurality of reflective surfaces and projected on a semiconductor wafer. The femtosecond laser light projected on a semiconductor wafer moves repeatedly along a same predetermined direction in a predetermined range during a predetermined time to groove or cut the semiconductor wafer.

Abstract: Disclosed herein is an all-digital phase and timing correction procedure for coherent averaging in dual-comb and multiheterodyne spectroscopy—applicable to any dual-comb spectroscopy setup. It can account for large frequency/phase instabilities of the used sources, yielding a significant reduction of the noise pedestal and an increase in signal-to-noise ratio (SNR) of the radio frequency (RF) beat notes. This technique is computationally efficient and can be conveniently implemented either as a post-processing algorithm or in a real-time data acquisition and processing platform without the necessity of adding any additional optical elements to the dual-comb spectroscopy system. By implementing this technique, the performance of any comb- or comb-like-source-based DCS system with a sufficient degree of mutual coherence between the optical modes can be improved in terms of SNR and number of spectroscopically-usable RF beat notes.

Abstract: Conventional etalon based spectrometers have either a limited range of evaluation wavelengths or require continuous scanning of the etalon. Conventional etalon based spectrometers also have limited contrast between the peak transmission of a frequency on resonance and the minimum transmission of a frequency off resonance. An improved optical spectrometer includes a cylindrical lens configured to converge the input beam of light in only one direction, whereby the input beam of light is focused along a focal line. Accordingly, a first etalon receives the input beam of light, and transmits a series of sub-beams, each sub-beam transmitted at a different angle from the normal, and each sub-beam including multiple frequencies based on the FSR, whereby a secondary dispersive element receives each sub-beam, and disperses each sub-beam into individual frequencies.

Abstract: An optical detection system for analyzing a fluid sample including a light source configured to emit a light beam to interact with the sample to form a spectrum, an optical fiber to transmit the spectrum, an array of single-photon detectors (SPDs), and wherein each SPD is configured to receive and is tunable to analyze spectral characteristics of the spectrum across a spectral range.

Abstract: Systems and methods of the present disclosure are directed to detecting species within a fluid using a multi-pass absorption cell and a spectrometer. The absorption cell includes a plurality of mirrors arranged in a manner such that a detection light traverses multiple passes through the fluid within the absorption cell. In some implementations, the detection light is reflected by the plurality of mirrors to form optical paths in more than one plane. The system also includes an electronic unit configured to receive and process spectral data from the spectrometer. In some implementations, the electronic unit communicates with at least one computational unit over a communication interface to send a portion of the spectral data for processing. The electronic unit may also receive processed data from the computational unit.

Abstract: A measurement apparatus includes: a projector configured to project pulse light or light whose intensity is periodically modulated onto a subject; an imaging sensor that includes a plurality of pixels, the imaging sensor being configured to image backscattered light of the light projected by the projector from the subject a plurality of times to output a plurality of image signals; a selection circuit configured to select, for each of the pixels, an image signal closest to a reference light amount from the plurality of image signals; and a characteristic calculation circuit configured to calculate, for each of the pixels, TOF information obtained when the image signal selected by the selection circuit is imaged, acquire light intensity information of the light projected by the projector, and calculate a characteristic of the subject based on the calculated TOF information and the acquired light intensity information.

Abstract: The present invention concerns an apparatus for spectral and intensity profile characterization comprising: a diffractive element; a beam block (3) attached to the diffractive element, the beam block (3) being positioned so as to block the passage of the direct incoming beam (1) which is not incident on the diffractive element; a device for translation of the beam block (3) and the diffractive element; reflective element (4); fixed detector (5) positioned on the axis of the incoming beam (1). The invention also concerns use and a method thereof. Such a compact system provides application in the field of spectrometry and diagnostics of the beam intensity profile, especially in the area of XUV and soft X-rays.

Abstract: A spectrometer includes a support having a bottom wall part in which a depression including a concave curved inner surface and a peripheral part adjacent to the depression are provided, and a side wall part disposed on a side on which the depression is open with respect to the bottom wall part, a light detection element supported by the side wall part while opposing the depression, and a dispersive part disposed on the inner surface of the depression. A length of the depression in a second direction in which a plurality of grating grooves included in the dispersive part is aligned is larger than a length of the depression in a third direction orthogonal to the second direction when viewed in a first direction in which the depression and the light detection element oppose each other. An area of the peripheral part adjacent to the depression in the second direction is larger than an area of the peripheral part adjacent to the depression in the third direction when viewed in the first direction.

Abstract: The present invention provides a method and a kit for half coating nanoparticles. According to the present invention, nanoparticles can be half coated in a relatively simple and economical process that can replace complicated processes, such as chemical synthesis, of a conventional Janus nanoparticle-preparing method.

Abstract: A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Abstract: A spectrometry device includes: an integrating sphere which includes an inner wall surface and an attachment hole; an adapter which includes a guide hole guiding the measurement target light and is disposed in the integrating sphere; a plate which includes a first surface covering the guide hole from the outside of the integrating sphere and allowing a sample to be mounted thereon and a second surface and through which the measurement target light is transmitted; a holder which includes a concave portion mounting the plate thereon and is attached to the attachment hole; and a spectral detector configured to detect the measurement target light. The concave portion includes a bottom surface facing the second surface and a side surface surrounding the periphery of the plate. The bottom surface and the side surface are coated with a reflective material reflecting the measurement target light.

Abstract: A supercontinuum radiation source comprises: a radiation source, an optical amplifier and a non-linear optical medium. The radiation source is operable to produce a pulsed radiation beam. The optical amplifier is configured to receive the pulsed radiation beam and increase an intensity of the pulsed radiation beam. The non-linear optical medium is configured to receive the amplified pulsed radiation beam and to broaden its spectrum so as to generate a supercontinuum radiation beam. The optical amplifier may supply a pump radiation beam to a gain medium, an intensity of the pump radiation beam being periodic and having a pump frequency that is an integer multiple of the frequency of the pulsed radiation beam. The optical amplifier may supply pump energy to a gain medium only when the pulses of the pulsed radiation beam propagate through the gain medium.

Abstract: Image acquisition apparatuses, spectral apparatuses, methods and storage mediums for use with same are provided herein. At least one apparatus includes: a diffraction element irradiated by a light; a fiber for receiving reflected scattered light from a subject; a diffraction grating dispersing the transmitted light into light fluxes of wavelength bands again; an optical system imaging the split light fluxes; and an imaging device near the focal point of the optical system. An image is changed by rotating the diffraction grating, from which a two-dimensional image is acquired. The transmitted light may be branched into two or more, and input to a collimator lens and imaged as multiple spectral sequences by the optical system. At least one apparatus may form light fluxes traveling at different angles; and may acquire spectral information of the reflected and scattered light. Preferably, for the luminous fluxes, no gap exists in an image.

Abstract: A device for tooth shade measurement comprising a housing, a handle and a measuring head, characterized in that said measuring head includes a hollow body extending along a longitudinal axis, said hollow body comprising a proximal end, a bent distal end relative to the longitudinal axis, said distal end being provided with a removable tip designed to come into contact with a tooth surface to be analyzed, at least one light source and image acquisition means, integral with the hollow body, said hollow body being adapted to transmit the light from said light source from the proximal end up to the distal end, and in that said device comprises an orientation assembly for mounting the proximal end of the hollow body in the housing so that the measuring head occupies different angular positions relative to the housing.

Abstract: An optoelectronic device configured for improved light extraction through a region of the device other than the substrate is described. A group III nitride semiconductor layer of a first polarity is located on the substrate and an active region can be located on the group III nitride semiconductor layer. A group III nitride semiconductor layer of a second polarity, different from the first polarity, can located adjacent to the active region. A first contact can directly contact the group III nitride semiconductor layer of the first polarity and a second contact can directly contact the group III nitride semiconductor layer of the second polarity. Each of the first and second contacts can include a plurality of openings extending entirely there through and the first and second contacts can form a photonic crystal structure. Some or all of the group III nitride semiconductor layers can be located in nanostructures.

Abstract: Disclosed are a food state measuring device, a food state measuring module, and a smart device including the same. The food state measuring device includes an optical spectrum acquiring unit configured to image a food to acquire an optical spectrum of the food, a database configured to store natural optical spectrum information for at least one food or a component of a food, and a control unit configured to measure a state of the food by comparing the natural optical spectrum stored in the database and the optical spectrum acquired by the optical spectrum acquiring unit.

Abstract: In one embodiment, a femtowatt sensitivity optical detector is provided using one or more photodiodes, intended as a replacement for the photomultiplier based photon counting unit.

Abstract: Spectral apparatus includes sensors that output signals indicating the respective energy amounts of a plurality of wavelength components. For each of the sensors, its reference spectral sensitivity is acquired, and an indicator indicating the reference spectral sensitivity of the sensor, is acquired. The deviation of an indicator indicating the spectral sensitivity of the sensor from the indicator indicating the reference spectral sensitivity of the sensor, is expressed by a linear function of an indicator indicating a mechanical error in the spectral apparatus. The indicator indicating the mechanical error in the spectral apparatus, is acquired to adapt a spectral sensitivity set of sensors to a signal set output by the sensors. For each of the sensors, the deviation of the indicator indicating the spectral sensitivity of the sensor from the indicator indicating the reference spectral sensitivity of the sensor, is acquired, so that the spectral sensitivity of the sensor is acquired.

Abstract: A spectrometer system may be used to determine one or more spectra of an object, and the one or more spectra may be associated with one or more attributes of the object that are relevant to the user. While the spectrometer system can take many forms, in many instances the system comprises a spectrometer and a processing device in communication with the spectrometer and with a remote server, wherein the spectrometer is physically integrated with an apparatus. The apparatus may have a function different than that of the spectrometer, such as a consumer appliance or device.

Abstract: Methods of performing dual-comb interferometry using a dual-comb interferometer and methods of characterizing a volume using dual-comb interferogram data are described.

Abstract: An analytical assembly within a unified device structure for integration into an analytical system. The analytical assembly is scalable and includes a plurality of analytical devices, each of which includes a reaction cell, an optical sensor, and at least one optical element positioned in optical communication with both the reaction cell and the sensor and which delivers optical signals from the cell to the sensor. Additional elements are optionally integrated into the analytical assembly. Methods for forming and operating the analytical system are also disclosed.

Abstract: A coal seam producibility determination system may include a fiber optic cable, the fiber optic extending from a DAS interrogation unit into a wellbore. The DAS interrogation unit may be located at a surface. The wellbore may intersect a plurality of coal seams to be measured, the coal seams comprising fluid and solubilized gas. The wellbore contains wellbore fluid and the wellbore has a wall. The fiber optic cable extends along the plurality of coal seams. The coal seam producibility determination system may further include a spectrometer, the spectrometer located at the surface or within the wellbore. The coal seam producibility determination system may also include an optical window, the optical window in optical communication with the spectrometer, the optical window in fluid communication with the wellbore fluid.

Abstract: A method for detecting a shipwrecked vessel and drown victims by using an aerial hyperspectral image, according to the present invention, comprises the steps of: (a) allowing an image reception unit to receive an observed aerial hyperspectral image, check whether the received aerial hyperspectral image is suitable for detection analysis, and extract observation information, and location information and a reflectance value for each pixel with respect to the detected shipwrecked vessel and drown victims; (b) allowing an image analysis unit to analyze spectral characteristic similarity between a spectral reflection value of a target object and an observed reflection value by using pre-constructed spectral library information and extract constituent materials and an occupation ratio for each pixel of the hyperspectral image, thereby classifying a detection result; and (c) allowing an image visualization unit to display the received hyperspectral image, locations of the detected shipwrecked vessel and drown victim

Abstract: A drive device includes a filter section that includes an optical filter, a transmission section that rotates around a rotation shaft, a first groove portion that is formed to the transmission section, a protruding portion that is formed to the filter section, in contact with the first groove portion, and that moves the filter section from a first position to a second position by moving along the first groove portion in coordination with rotation of the transmission section, and a second groove portion that is formed continuously with the first groove portion, and that is provided along a tangent line direction passing through the protruding portion that is on a circle having the rotation shaft of the transmission section at a center and a radius that is a distance between the rotation shaft and the protruding portion, when the optical filter section is moved to the second position.

Abstract: A hand held spectrometer is used to illuminate the object and measure the one or more spectra. The spectral data of the object can be used to determine one or more attributes of the object. In many embodiments, the spectrometer is coupled to a database of spectral information that can be used to determine the attributes of the object. The spectrometer system may comprise a hand held communication device coupled to a spectrometer, in which the user can input and receive data related to the measured object with the hand held communication device. The embodiments disclosed herein allow many users to share object data with many people, in order to provide many people with actionable intelligence in response to spectral data.

Abstract: An heterodyne apparatus and method for measuring performance parameters of a coherent optical receiver at RF frequencies is disclosed. Two coherent lights are launched into signal and LO ports of the receiver with an optical frequency offset f. One of the lights is modulated in amplitude at a test modulation frequency F. COR performance parameters are determined by comparing two frequency components of the COR output. CMRR is determined based on a strength of a direct detection spectral line at the modulation frequency relative to that of spectrally-shifted lines at (F±f). GDV information is obtained by modulating one of the lights at two phase-locked frequencies, such as F and 2F, and comparing phases of two time-domain traces corresponding to frequency components of the COR output signal at the two frequencies.

Abstract: A meta-lens having a phase profile includes a substrate and a plurality of nanostructures disposed on the substrate. The nanostructures together define the phase profile of the meta-lens. The phase profile achieves an off-axis focus. Each nanostructure is designed according to at least one design parameter of the nanostructure that imparts a phase shift of light passing through the nanostructure.