Abstract: Multimode light detectors are provided, which combine a plurality of measurements of light to detect information, using a mode transformation device. The light may be light from one or more objects, and the mode transformation device may be configured to transform the light into many single mode light beams. Each measurement of the light may be a measurement of a corresponding single mode light beam. The multimode detectors may include one or more optical receivers, configured to mix one or more single mode light beams with one or more local oscillators, respectively. Methods are provided for detecting information of objects, including obtaining light from the objects, transforming the light into multiple single mode light beams, and collecting (and/or combining) measurements of the single mode light beams.

Abstract: Wavenumber linear spectrometers are provided including an input configured to receive electromagnetic radiation from an external source; collimating optics configured to collimate the received electromagnetic radiation; a dispersive assembly including first and second diffractive gratings, wherein the first diffraction grating is configured in a first dispersive stage to receive the collimated electromagnetic radiation and wherein the dispersive assembly includes at least two dispersive stages configured to disperse the collimated input; and an imaging lens assembly configured to image the electromagnetic radiation dispersed by the at least two dispersive stages onto a linear detection array such that the variation in frequency spacing along the linear detection array is no greater than about 10%.

Abstract: A scanning mirror includes a mirror unit configured to reflect a laser beam, a supporter configured to cause the mirror unit to rotate and oscillate, and an oscillation sensor configured to output a monitor signal indicating oscillation of the mirror unit. A photodetector detects an intensity of the laser beam. When a value of the monitor signal falls out of a predetermined range of a normal operation and a value of the intensity detected by the photodetector fails to decrease, a breaking signal for causing the supporter to oscillate more than a breaking limit angle of the supporter is input. This scanning mirror and an image projection device using this scanning mirror can display an image at sufficient brightness safely.

Abstract: A multi-channel imaging spectrometer and method of use thereof. One example of the multi-channel imaging spectrometer includes a single entrance slit, a double pass reflective triplet and at least a pair of diffraction gratings. The spectrometer is configured to receive and collimate an input beam from the entrance slit, to split the collimated beam into two spectral sub-bands using a beamsplitter, and to direct each sub-band to one of the pair of diffraction gratings. The diffraction gratings are each configured to disperse the received portion of the collimated beam into its constituent colors, and redirect the dispersed outputs through the reflective triplet to be imaged into an image sensor located at a focal plane aligned with the entrance slit.

Abstract: Exemplary embodiments of apparatus and method according to the present disclosure are provided. For example, an apparatus for providing electromagnetic radiation to a structure can be provided. The exemplary apparatus can include a first arrangement having at least two wave-guides which can be configured to provide there through at least two respective electromagnetic radiations with at least partially different wavelengths from one another. The exemplary apparatus can also include a dispersive second arrangement structured to receive the electro-magnetic radiations and forward at least two dispersed radiations associated with the respective electro-magnetic radiations to at least one section of the structure. The wave-guide(s) can be structured and/or spatially arranged with respect to the dispersive arrangement to facilitate at least partially overlap of the dispersed radiations on the structure.

Abstract: A method for imaging a sample. The method includes, during a single acquisition event, receiving depth-encoded electromagnetic (EM) fields from points on a sample that includes a first depth-encoded EM field for a first point and a second depth-encoded EM field for a second point, and redirecting the first depth-encoded EM field along a first predetermined direction to a first location on a dispersing re-imager and the second depthencoded EM field along a second pre-determined direction to a second location on the dispersing re-imager. The method further includes spectrally dispersing the first depthencoded EM field to obtain a first spectrum, re-imaging the first spectrum onto a first location on a detector, spectrally dispersing the second depth-encoded EM field to obtain a second spectrum, re-imaging the second spectrum onto a second location on the detector, and detecting the first re-imaged spectrum and the second re-imaged spectrum.

Abstract: A method for imaging a sample, the method includes, during a single acquisition event, receiving a first polarization-encoded EM field for a first point and a second polarization-encoded EM field for a second point. The method further includes re-directing the first polarization-encoded EM field along a first pre-determined direction to a first location on a dispersing re-imager and the second polarization-encoded EM field along a second pre-determined direction to a second location on the dispersing re-imager. The method further includes spectrally dispersing the first polarization-encoded EM field to obtain a first spectrum, re-imaging the first spectrum onto a first location on a detector, spectrally dispersing the second polarization-encoded EM field to obtain a second spectrum, re-imaging the second spectrum onto a second location on the detector, and detecting the first re-imaged spectrum and the second re-imaged spectrum.

Abstract: A multispectral imaging system and method in which the zero-mode channel is used to provide imaging of any of a variety of optical properties. In one example an imaging method includes spectrally dispersing received electromagnetic radiation into its spectral components with a dispersive element to produce spectrally dispersed electromagnetic radiation, transmitting the electromagnetic radiation through the dispersive element to produce non-dispersed electromagnetic radiation corresponding to a zero order diffraction mode of the dispersive element, imaging the non-dispersed electromagnetic radiation to produce a zero-mode image, and simultaneously imaging the spectrally dispersed electromagnetic radiation to produce a spectral image.

Abstract: Various embodiments of apparatuses, systems and methods are described herein for a spectrometer comprising at least two dispersive elements configured to receive at least one input optical signal and generate two or more pluralities of spatially separated spectral components, at least a portion of the at least two dispersive elements being implemented on a first substrate; and a single detector array coupled to the at least two dispersive elements and configured to receive and measure two or more pluralities of narrowband optical signals derived from the two or more pluralities of spatially separated spectral components, respectively.

Abstract: A spectral characteristic acquisition device includes a light irradiation part configured to irradiate an object with light, a diffraction part configured to diffract light reflected from the object to provide diffracted light, a light-receiving part configured to receive the diffracted light and output a signal based on an amount of the diffracted light, a calibration color index configured to include a color with a known spectral characteristic, and an operation part configured to calculate a spectral characteristic of the object from a signal output from the light-receiving part by using a predetermined transformation matrix and calibrate the transformation matrix by using the calibration color index.

Abstract: A method of manufacturing a solid-state imaging element includes: manufacturing an element chip in which photoelectric conversion units are arranged on a main surface side; preparing a base configured using a material with an expansion coefficient greater than the element chip and having an opening of which the periphery of the opening is shaped as a flat surface; expanding the base by heating, mounting the element chip on the flat surface of the base in a state where the opening of the base is covered; and three-dimensionally curving a portion corresponding to the opening in the element chip by cooling and contracting the base in a state where the element chip is fixed to the flat surface of the expanded base.

Abstract: A method for creating an energy series of images acquired using a multi-energy computed tomography (CT) imaging system having a plurality of energy bins includes acquiring, with the multi-energy CT imaging system, a series of energy data sets, where each energy data set is associated with at least one of the energy bins. The method includes producing a conglomerate image using at least a plurality of the energy data sets and, using the conglomerate image, reconstructing an energy series of images, each image in the energy series of images corresponding to at least one of the energy data sets.

Abstract: A hyperspectral imaging system and a method are described herein for providing a hyperspectral image of an area of a remote object (e.g., scene of interest). In one aspect, the hyperspectral imaging system includes at least one optic, a rotatable disk (which has at least one spiral slit formed therein), a spectrometer, a two-dimensional image sensor, and a controller. In another aspect, the hyperspectral imaging system includes at least one optic, a rotatable disk (which has multiple straight slits formed therein), a spectrometer, a two-dimensional image sensor, and a controller. In yet another aspect, the hyperspectral imaging system includes at least one optic, a rotatable drum (which has a plurality of slits formed on the outer surface thereof and a fold mirror located therein), a spectrometer, a two-dimensional image sensor, and a controller.

Abstract: A compact spectrometer apparatus for characterizing a microscope illumination source in real time, and without interfering with the observation and/or characterization of a sample under observation with the microscope. The spectrometer apparatus is comprised of a light probe comprising a mirror disposed in a housing, the mirror positioned to reflect light from the illumination source into an optical coupling; an optical waveguide receiving reflected light into the optical coupling; and a spectrometer comprising a light sensor receiving reflected light directed by the optical waveguide from the optical coupling of the light probe, the sensor adapted to sense light over a range of wavelengths and output a signal indicative of the intensity of the light at any wavelength over the range.

Abstract: The present disclosure provides a spectrometer. In one aspect, the spectrometer includes at least one slit element located at an object plane, an optical sub-system having at least one optical element, at least one dispersive element, and at least one detecting element located substantially at an image plane. The optical sub-system is configured to substantially collimate, at said dispersive element, electromagnetic radiation emanating from said at least one slit element, configured to substantially image the substantially collimated electromagnetic radiation from said dispersive element onto the image plane, and configured to have a substantially variable focal length.

Abstract: Systems, including methods, apparatus, and algorithms, for spectrally imaging a two-dimensional array of samples.

Abstract: In a spectroscopic module 1, a flange 7 is formed integrally with a diffraction layer 6 along a periphery thereof so as to become thicker than the diffraction layer 6. As a consequence, at the time of releasing a master mold used for forming the diffraction layer 6 and flange 7, the diffraction layer 6 formed along a convex curved surface 3a of a main unit 3 can be prevented from peeling off from the curved surface 3a together with the master mold. A diffraction grating pattern 9 is formed so as to be eccentric with respect to the center of the diffraction layer 6 toward a predetermined side. Therefore, releasing the mold earlier from the opposite side of the diffraction layer 6 than the predetermined side thereof can prevent the diffraction layer 6 from peeling off and the diffraction grating pattern 9 from being damaged.

Abstract: A spectroscopic module 1 is provided with a spectroscopic unit 8 and a photodetector 9 in addition to a spectroscopic unit 4 and a photodetector 5 and thus can enhance its detection sensitivity for light in a wide wavelength range or different wavelength regions of light. A light-transmitting hole 5b and a light-absorbing layer 12 are disposed between light detecting portions 5a, 9a, while a reflection unit 7 is provided so as to oppose the layer 12 (i.e., region R), whereby the size can be kept from becoming larger. Ambient light La is absorbed by the layer 12. Any part of the light La transmitted through the region R in the layer 12 is reflected to the region R by the unit 7 formed so as to oppose the region R, whereby stray light can be inhibited from being caused by the incidence of the light La.

Abstract: This disclosure relates to a method for analyzing a sample of material. The method includes (a) converting a portion of the sample into a plasma multiple times; (b) recording a spectrum of electromagnetic radiation emitted in response to each of the sample conversions to define a sequence of spectra for the sample, in which each member of the sequence corresponds to the spectrum recorded in response to a different one of the sample conversions; (c) using an electronic processor to compare the sequence of spectra for the sample to a sequence of spectra for each of at least one reference sample in a reference library; and (d) using the electronic processor to determine information about the sample based on the comparison to the reference samples in the library.

Abstract: Methods of determining a known location of a sensor head in a scanner without the use of contact sensors are described. Upon initialization of a scanner, the sensor head is moved rapidly to quickly detect a known pattern at a known location in the scanner. As the scan head is moved, windows moving along lines of pixels detected by the sensor head are used to perform pixel averaging to detect the known pattern in the scanner. Parameters associated with the windows custom fit the windows to the known pattern to facilitate rapid detection of the known pattern and determine a known location of the scan head to facilitate calibration of the scanner.

Abstract: A spectrometer that includes a grating that disperses light via Fresnel diffraction according to wavelength onto a sensing area that coincides with an optical axis plane of the grating. The sensing area detects the dispersed light and measures the light intensity associated with each wavelength of the light. Because the spectrometer utilizes Fresnel diffraction, it can be miniaturized and packaged as an integrated circuit.

Abstract: A transmissive diffraction grating includes a polarization conversion layer, a first diffractive layer disposed on one surface side of the polarization conversion layer, and a second diffractive layer disposed on the other surface side of the polarization conversion layer. Both the first diffractive layer and the second diffractive layer include refractive index modulation structures arranged with a period P in a first direction, and diffraction efficiency for a TE polarized light component is higher than a diffraction efficiency for a TM polarized light component.

Abstract: A method of adjusting a resolution of a multidimensional imaging system includes taking a first hyperspectral snapshot by the multidimensional imaging system comprising a light processor comprising a plurality of optical fibers having a first end with an input spacing and a second end with an adjustable output spacing; adjusting the adjustable output spacing of the light processor to a new output spacing; and taking a second hyperspectral snapshot after adjusting the adjustable spacing of the multidimensional imagining system.

Abstract: An apparatus for performing Raman spectral analysis of a sample is described, comprising a coherent light source, an first optical chain to direct the coherent light to impinge on the sample, a second optical chain to direct the scattered light onto a diffraction grating, and a third optical chain to direct the diffracted light onto detection array. The diffraction grating is a stairstep with a metalized surface, and a plurality of metalized stripes on a flat surface is disposed in a direction orthogonal to the long dimension of the stairsteps. The region between the flat surface and the stairstep is transparent. The zeroth-order fringe is selected by a slit and directed onto camera. The resultant interferogram is Fourier transformed to produce a representation of the Raman spectrum.

Abstract: A spectroscopic imaging device adjusting method adjusts a relative arrangement relationship among a collimating lens, a diffraction grating, a condensing lens and an array type light receiving part so as to maximize the value of the following expression (1) for an output values ƒn from respective light receiving sensors Pn when monochromatic light is inputted to a spectroscopic imaging device, wherein ?>1 and n is each integer equal to or larger than 1 and equal to or smaller than N.

Abstract: The present application discloses a system comprising a compact curved grating (CCG) and its associated compact curved grating spectrometer (CCGS) or compact curved grating wavelength multiplexer/demultiplexer (WMDM) module and a method for making the same. The system is capable of achieving a very small (resolution vs. size) RS factor. The location of the entrance slit and detector can be adjusted in order to have the best performance for a particular design goal. The initial groove spacing is calculated using a prescribed formula dependent on operation wavelength. The location of the grooves is calculated based on two conditions.

Abstract: A quantum cascade laser (QCL) may include a QCL crystal having an emitting facet, and an active region adjacent the emitting facet, the emitting facet for providing an electromagnetic beam. The QCL may include an optical cavity comprising a mirror being external to the QCL crystal, and for redirecting the electromagnetic beam into the active region of the QCL crystal to provide optical feedback, and a driver circuit for driving the QCL crystal with a constant current. The QCL may include a controller coupled to the optical cavity and for dynamically and autonomously aligning the optical cavity based upon an error signal from the QCL crystal to maintain stable the optical feedback into the active region of the QCL crystal.

Abstract: A robot apparatus includes a gripping unit configured to grip a first component, a force sensor configured to detect, as detection values, a force and a moment acting on the gripping unit, a storing unit having stored therein contact states of the first component and a second component and transition information in association with each other, a selecting unit configured to discriminate, on the basis of the detection values, a contact state of the first component and the second component and select, on the basis of a result of the discrimination, the transition state stored in the storing unit, and a control unit configured to control the gripping unit on the basis of the transition information selected by the selecting unit.

Abstract: An optical spectrum analyzer is implemented with a detector combined with a tunable filter mounted on a stage capable of 360-degree rotation at a constant velocity. Because of the constant rate of angular change, different portions of the input spectrum are detected at each increment of time as a function of filter position, which can be easily measured with an encoder for synchronization purposes. The unidirectional motion of the mirror permits operation at very high speeds with great mechanical reliability. The same improvements may be obtained using a diffraction grating or a prism, in which case the detector or an intervening mirror may be rotated instead of the grating or prism.

Abstract: There is provided a high-accuracy automatic analysis device achieving both of measurement in a wide concentration range and high sensitivity at a low concentration. The signals of a plurality of wavelengths ?1 to ?12 where the sensitivity of light absorption caused by fine particles is high from a light source 40 are converted to absorbances by a spectroscopic optical system (detector) 41. The absorbances are converted to a secondary parameter from in which a noise component is cancelled by using a previously-defined conversion table 54, so that a concentration of a measured material (predetermined component) is calculated by an operation unit (calculating means) 53 based on the secondary parameter. Thus, analysis being resistant to the noise even at the low concentration can be achieved in a range up to a high concentration.

Abstract: A spectrometer in accordance with the present disclosure may provide multiple optical paths from the inputs to the camera, where the paths are as nearly identical as possible. For example, a spectrometer in accordance with the present disclosure may include multiple inputs, input optics, a diffraction grating, output optics, and a camera. The multiple inputs may be imaged onto different sections of the camera using the same input optics, the same diffraction grating, and the same output optics.

Abstract: Spectral device includes: diffraction element which disperses light for each wavelength; optical condensing system which condenses diffracted light of specific order generated by diffraction in the diffraction element; photo-detector arranged at position where the diffracted light of the specific order is condensed by the optical condensing system; first deflection device which inverts the direction of travel of second light as zeroth-order diffracted light generated by diffraction of first light which has entered the diffraction element as parallel luminous flux, and leads the second light into the diffraction element; and second deflection device which deflects the diffracted light of the specific order generated by diffraction of the second light which has entered the diffraction element in the same direction as the diffracted light of the specific order generated by the diffraction of the first light, and leads the deflected light into the optical condensing system.

Abstract: A spectrometer includes: a collimating element configured for collimating a beam of light into a first one of a cross-dispersing element and an echelle grating, the grating in optical communication with the cross-dispersing element; a focusing element for receiving the light from a second one of the cross-dispersing element and the echelle grating and focusing wavelengths of the light onto a spatial light modulator; the spatial light modulator configured for selectively directing the wavelengths onto a detector for detection. A method of use and the method of fabrication are provided.

Abstract: Large digital displays for entertainment, architectural and advertizing displays have interconnected display panels with pluralities of light emitting elements. To solve calibration problems, each of the display panels stores measured luminance and chromaticity data for each of the light emitting elements of the panel. The luminance data is independent of the chromaticity data. A central controller can then perform calibration procedures so that the light emitting elements are matched across the entire display.

Abstract: A hyperspectral imaging system and method are described herein for providing a hyperspectral image of an area of a remote object (e.g., scene of interest). The hyperspectral imaging system includes at least one optic, a scannable slit mechanism, a spectrometer, a two-dimensional image sensor, and a controller. The scannable slit mechanism can be a micro-electromechanical system spatial light modulator (MEMS SLM), a diffractive Micro-Opto-Electro-Mechanical Systems (MOEMS) spatial light modulator (SLM), a digital light processing (DLP) system, a liquid crystal display, a rotating drum with at least one slit formed therein, or a rotating disk with at least one slit formed therein.

Abstract: Apparatuses and method for real-time measuring ultrashort pulse shape and pulse width. Transient-grating effect on a transparent optical medium is used to generate a reference beam. A black plate with four equal-sized holes divides the incoming laser beam into four beams, one of which is attenuated and introduced an appropriate time delay relative to the other three. The four laser beams pass through a concave mirror and are focused onto a nonlinear transparent optical medium. The three beams without attenuation are used to generate a transient-grating light in the transparent medium. The transient-grating light is collinear and overlapped with the fourth attenuated beam. According to the third-order nonlinear effect, the transient-grating light has a broader spectral bandwidth and more smooth spectrum phase with respect to the incident laser. By measuring the spectral interference, the spectrum and spectral phase may be retrieved by spectral interferometry.

Abstract: The invention relates to a spectrometer comprising a hollow main optical body having at least one light channel, a light source, a diffraction grating having a grating central point, a light inlet opening, and a detector unit, which are arranged in such a way that the focal curve of the spectrometer satisfies the back focus equation. In order to create a spectrometer having sufficient spectral resolution from a low-price, light, and easy-to-process material, which spectrometer is able to operate in a large temperature interval even without thermostatic control, according to the invention the light inlet opening is arranged on a compensation body, the compensation body is arranged in the light channel and fastened to the main optical body between the light source and the diffraction grating, and the compensation body is dimensioned in such a way that the compensation body changes the distance between the light inlet opening and the grating central point when the main optical body thermally expands.

Abstract: A method for fabricating a grating coupler having a bottom mirror in a semiconductor wafer including etching a trench from a top surface of a wafer and around a grating coupler formed in the wafer; etching a void underneath the grating coupler; etching a via into the void from the backside of the wafer; and depositing a mirror on the bottom of the grating coupler. Alternatively, additional oxide may be deposited on the bottom of the grating coupler prior to the deposition of the mirror such that a desirable oxide thickness on the bottom is achieved.

Abstract: Provided is a detection optical system that is provided with a dispersed-light detection function and that can increase the amount of detected light by enhancing the diffraction efficiency. A detection optical system is employed which includes a transmissive VPH diffraction grating that disperses fluorescence from a specimen into a plurality of wavelength bands; a rotating mechanism that rotates the VPH diffraction grating about an axial line that is perpendicular to an incident optical axis of the fluorescence from the specimen and an emission optical axis from the VPH diffraction grating; a light detection portion that detects the fluorescence from the specimen that has been dispersed by the VPH diffraction grating; and a correcting portion that corrects an incident position on the light detection portion in accordance with a displacement of the optical axis caused by the rotation of the VPH diffraction grating in synchronization with the rotating mechanism.

Abstract: The compact microspectrometer for fluid media has, in a fixed spatial coordination in a housing, a light source, a fluid channel, a reflective diffraction grating, and a detector. The optical measuring path starting from the light source passes through the fluid channel and impinges on the diffraction grating. The spectral light components reflected by the diffraction grating impinge on the detector.

Abstract: The invention provides an energy dispersion device, spectrograph and method that can be used to evaluate the composition of matter on site without the need for specialized training or expensive equipment. The energy dispersion device or spectrograph can be used with a digital camera or cell phone. A device of the invention includes a stack of single- or double-dispersion diffraction gratings that are rotated about their normal giving rise to a multiplicity of diffraction orders from which meaningful measurements and determinations can be made with respect to the qualitative or quantitative characteristics of matter.

Abstract: A spectral characteristic acquiring apparatus is provided which includes: an area dividing part; a spectrum separating part; a light receiving part; and a calculating part, wherein the calculating part includes a transformation matrix storing part that stores a transformation matrix used for calculating the spectral characteristic corresponding to electrical signals of a first diffraction pattern group including two or more adjacent diffraction patterns, and a spectral characteristic calculating part that calculates, based on the electrical signals of the first diffraction pattern group and the corresponding transformation matrix, the spectral characteristic at the locations of the image carrying medium corresponding to the apertures of the first diffraction pattern group.

Abstract: Provided is a snapshot spectral domain optical coherence tomographer comprising: a light source providing a plurality of beamlets; a beam splitter, splitting the plurality of beamlets into a reference arm and a sample arm; a first optical system that projects the sample arm onto multiple locations of a sample; a second optical system for collection of a plurality of reflected sample beamlets; a third optical system projecting the reference arm to a reflecting surface and receiving a plurality of reflected reference beamlets; a parallel interferometer that provides a plurality of interferograms from each of the plurality of sample beamlets with each of the plurality of reference beamlets; an optical image mapper configured to spatially separate the plurality of interferograms; a spectrometer configured to disperse each of the interferograms into its respective spectral components and project each interferogram in parallel; and a photodetector providing photon quantification.

Abstract: A low-cost optics, broadband, astigmatism-corrected practical spectrometer. An off-the-shelf cylindrical lens is used to remove astigmatism over the full bandwidth, providing better than 0.1 nm spectral resolution and more than 50% throughput over a bandwidth of 400 nm centered at 800 nm. The spectrometer includes a first spherical mirror disposed along an optical path in an off-axis (tilted) orientation; a diffraction grating disposed along the optical axis in a location optically downstream from the first mirror; a second spherical mirror disposed along the optical path in an off-axis orientation in a location optically downstream from the diffraction grating; a cylindrical optic disposed in the optical path; and a detector disposed in the optical path in a location optically downstream from the second spherical mirror.

Abstract: A spectrometer assembly (10), comprising an Echelle grating (18; 46) for dispersing radiation entering the spectrometer assembly (10) in a main dispersion direction, and a dispersion assembly (16; 40) for dispersing a parallel radiation bundle generated from the radiation entering the spectrometer assembly in a lateral dispersion direction, is characterized in that the dispersion assembly (16; 40) is reflective, and the dispersion assembly (16; 40) is arranged relative to the Echelle grating (18; 46) in such a way that the parallel radiation bundle is reflected in the direction of the Echelle grating. The Echelle grating (18; 46) may be arranged in such a way that the dispersed radiation is reflected back to the dispersion assembly (16; 40).

Abstract: Systems and methods for determining information for a wafer are provided. One system includes a first grating that diffracts light from a wafer having wavelengths in a first portion of a broadband range and does not diffract the light from the wafer having wavelengths in a second portion of the broadband range. The system also includes a second grating positioned in the path of the light that is not diffracted by the first grating. The second grating diffracts the light from the wafer having the wavelengths in the second portion of the broadband range. The system further includes a first detector configured to generate first output responsive to the light diffracted by the first grating and a second detector configured to generate second output responsive to the light diffracted by the second grating.

Abstract: Wavenumber linear spectrometers are provided including an input configured to receive electromagnetic radiation from an external source; collimating optics configured to collimate the received electromagnetic radiation; a dispersive assembly including first and second diffractive gratings, wherein the first diffraction grating is configured in a first dispersive stage to receive the collimated electromagnetic radiation and wherein the dispersive assembly includes at least two dispersive stages configured to disperse the collimated input; and an imaging lens assembly configured to image the electromagnetic radiation dispersed by the at least two dispersive stages onto a linear detection array such that the variation in frequency spacing along the linear detection array is no greater than about 10%.

Abstract: Embodiments of the invention provide a device called a “G-Fresnel” device that performs the functions of both a linear grating and a Fresnel lens. We have fabricated the G-Fresnel device by using PDMS based soft lithography. Three-dimensional surface profilometry has been performed to examine the device quality. We have also conducted optical characterizations to confirm its dual focusing and dispersing properties. The G-Fresnel device can be useful for the development of miniature optical spectrometers as well as emerging optofluidic applications. Embodiments of compact spectrometers using diffractive optical elements are also provided. Theoretical simulation shows that a spectral resolution of approximately 1 nm can be potentially achieved with a millimeter-sized G-Fresnel. A proof-of-concept G-Fresnel-based spectrometer with subnanometer spectral resolution is experimentally demonstrated.

Abstract: The present application discloses a system comprising a compact curved grating (CCG) and its associated compact curved grating spectrometer (CCGS) or compact curved grating wavelength multiplexer/demultiplexer (WMDM) module and a method for making the same. The system is capable of achieving a very small (resolution vs. size) RS factor. In the invention, the location of the entrance slit and detector can be adjusted in order to have the best performance for a particular design goal. The initial groove spacing is calculated using a prescribed formula dependent on operation wavelength. The location of the grooves is calculated based on two conditions. The first one being that the path-difference between adjacent grooves should be an integral multiple of the wavelength in the medium to achieve aberration-free grating focusing at the detector or output slit (or output waveguide) even with large beam diffraction angle from the entrance slit or input slit (or input waveguide).

Abstract: A spectrometer includes: a collimating element configured for collimating a beam of light into a first one of a cross-dispersing element and an echelle grating, the grating in optical communication with the cross-dispersing element; a focusing element for receiving the light from a second one of the cross-dispersing element and the echelle grating and focusing wavelengths of the light onto a spatial light modulator; the spatial light modulator configured for selectively directing the wavelengths onto a detector for detection. A method of use and the method of fabrication are provided.