Abstract: An apparatus for simultaneously measuring linear and circular polarization components of light is provided, and contains no moving parts. The apparatus may include a prism assembly configured to receive collimated light and splits the light into different directions according to its polarization state. The apparatus may also include lenses configured to collimate light from an image plane to be analyzed by the prism assembly, or direct the light that is split by the prism assembly to different detectors or locations on an image plane.

Abstract: The invention concerns an electronic method for extracting the amplitude ES and the phase ?S of an electrical signal in a synchronous detector, the signal containing a modulated part Imod of the form Imod ? ES f(t)*cos(?S??R(t)), where ?R(t) and f(t) are two known temporal modulation functions. The method comprises the following steps: multiplying the signal by two reference signals C(t) and S(t) constructed from ?R(t) and f(t); integrating the resulting signals over a time tint; determining the amplitude and phase of said signal from the quantities X and Y resulting from the previous integrations. The method is characterised in that: said electrical signal is multiplied by C(t) and S(t) that can be decomposed on the same set of frequencies as those present in Imod. The invention also concerns the application of the above method in interferometric circuits and the use and execution of the above method.

Abstract: Exemplary embodiments of the present disclosure include a combined catheter-based optical coherence tomography-two-photon luminescence (OCT-TPL) imaging system. Exemplary embodiments further include methods to detect, and further characterize the distribution of cellular components (e.g., macrophage, collagen/elastin fiber, lipid droplet) in thin-cap fibroatheromas with high spatial resolution in vivo.

Abstract: Data measured by PS-OCT is corrected in a non-linear manner to enhance the quantitative analysis capability of PS-OCT and permit accurate quantitative diagnosis, including diagnosis of disease stage of lesions, as a useful means for computer diagnosis. Even when retardation per PS-OCT 1 contains error and becomes noise and its distribution is not normal or symmetrical around the true value, measured data is converted using a distribution conversion function obtained by analyzing the characteristics of noise via Monte Carlo simulation to remove the systematic error and estimate the true value otherwise buried in noise and thereby correct the PS-OCT 1 image more clearly.

Abstract: The present invention relates to a laser sensor for self-mixing interferometry. The laser sensor comprises at least one semiconductor laser light source emitting laser radiation and at least one photodetector (6) monitoring the laser radiation of the laser light source. The laser light source is a VECSEL having a gain medium (3) arranged in a layer structure (15) on a front side of a first end mirror (4), said first end mirror (4) forming an external cavity with an external second end mirror (5). The proposed laser sensor provides an increased detection range and can be manufactured in a low-cost production process.

Abstract: An active heterodyne detection system comprises a continuously tuneable laser source (1) emitting infra-red radiation, means (8) to split the infra-red radiation into a first part and a second part, means (4) to provide a frequency shift between the first part and the second part, means (8, 9) to direct the first part of the infra-red radiation to a target (2), means (4) to provide the second part of the infra-red radiation as a local oscillator, means (8, 9) to collect a scattered component of the first part of the infra-red light from the target (2), and means (5) to mix the scattered component and the local oscillator and route them to a detector (3) for heterodyne detection over a continuous spectral range. A method of active heterodyne detection over a continuous spectral range is also disclosed.

Abstract: An object of the present invention is to provide an optical inspection apparatus that suppresses an influence of quantum noise and obtains superior defect detection performance even when an amount of light is small and a method thereof. In order to resolve the above problem, the present invention provides an optical inspection apparatus that includes a light source which radiates light to a sample; a light interference device which causes target light transmitted, scattered, or reflected from the sample and reference light to interfere with each other, such that strength of light after the interference becomes lower than strength of the target light; a photon counter which measures a photon number of the light after the interference by the light interference device; and a defect identifier which identifies the presence or absence of a defect, on the basis of a detected photon number obtained by the photon counter.

Abstract: An optical coherence tomography system utilizes an optical swept source that frequency scans at least two different sweep rates. In this way, the system can perform large depth scans of the sample and then the same system can perform shorter depth high precision scans, in one specific example. In order to optimally use the analog to digital converter that samples the interference signal, the system further samples the interference signals at different optical frequency sampling intervals depending upon the selected sweep rates of the optical swept source. This allows the system to adapt to different sweep rates in an optimal fashion.

Abstract: A method for determining a presence of a locking signal in a signal received by an optical receiver device, the optical receiver device configured to be used in an optical communications network, the locking signal being a signal exchanged by optical communication devices of the optical communications network in a phase preceding setting up communications between the optical communication devices. The presence of the locking signal is determined by obtaining a direct current component or a component at twice a frequency at which the locking signal is supposed to be modulated, and by obtaining a contribution of the communication signal, if any, on the component.

Abstract: A pulse laser oscillator (11) outputs a first laser beam, a beam splitter splitting the first laser beam into split beams, optical paths (12, 13, 14, 15, 16) propagating light of split beams split, respectively, taking different times for light propagation thereof, a condenser superimposing light of split beams propagated through the optical paths, respectively, on an identical spot of a measuring material (100), for irradiation therewith, a laser interferometer (30) irradiating the measuring material (100) with light of a second laser beam, having light intensity variations resulted from interferences between reference light and light of the second laser beam reflected or scattered, as bases to detect ultrasonic waves energized by light of the first laser beam and transmitted in the measuring material (100), a waveform analyzer (32) calculating a metallic microstructure or a material property of the measuring material (100) based on ultrasonic waves.

Abstract: An encoder interferometry system includes a beam splitting element positioned to receive an input beam from a light source, in which the beam splitting element is configured to direct a first portion of the input beam along a measurement path to define a measurement beam and a second portion of the input beam along a reference path to define a reference beam, an encoder scale positioned to diffract the measurement beam at least once, one or more optical components configured and arranged to alter a direction of a first diffracted portion of the measurement beam and a direction of a second diffracted portion of the measurement beam such that beam paths of the first diffracted portion and the second diffracted portion are non-parallel subsequent to the first diffracted portion and the second diffracted portion passing through the beam splitting element, and a detector positioned to receive the first diffracted portion.

Abstract: An apparatus and method for inspecting a graphene board. The graphene board inspecting apparatus for inspecting a graphene board on which at least one graphene layer is formed includes: a light processing unit which emits at least one light on the graphene board, receives the at least one light penetrating the graphene board and converts the received at least one light to an output signal; a transmittance detecting unit which receives the output signal from the light processing unit to inspect a transmittance of the at least one light penetrating the graphene board; and a determination unit which is connected to the transmittance detecting unit and receives the detected transmittance to determine a state of the graphene board by analyzing the detected transmittance.

Abstract: An interferometer is provided that includes a first path and a second path. The first path is configured to propagate an electro-magnetic signal at a first wavelength. The second path is configured to convert a portion of the electro-magnetic signal from the first wavelength to a second wavelength for processing and is configured to convert the portion of the electro-magnetic signal from the second wavelength back to the first wavelength for interference with the electro-magnetic signal of the first path. The first wavelength may be an optical wavelength or any other suitable wavelength of the electro-magnetic spectrum. The second wavelength, which is different than the first wavelength, also may be any suitable wavelength of the electro-magnetic spectrum.

Abstract: Provided is a photoacoustic microscope, including: an objective lens configured to collect excitation light into a specimen, the excitation light in a wavelength range that is absorbed by an object to be observed; a detection light optical system configured to (i) form an image of a point light source of detection light in a middle portion of a pupil of the objective lens, the detection light having a wavelength that is different from the wavelength range of the excitation light, and (ii) emit the detection light onto the specimen by means of the objective lens; an optical scanning unit configured to deflect the excitation light and the detection light that enter the objective lens, for scanning the specimen; and a light detection unit configured to detect reflected light of the detection light that is reflected by the specimen.

Abstract: A multiband spatial heterodyne spectrometer for determining spectra in first and second wavelength bands has a beamsplitter configured to split incident light and to direct the incident light upon a first and a second diffraction grating. The gratings are configured for Littrow reflection of incident light of the first wavelength band at a first order and Littrow reflection of incident light of the second wavelength band at a second order. Light reflected by the first and the second diffraction grating forms diffraction patterns imaged by an electronic camera. A dispersive device separates the imaged interference patterns onto separate groups of pixel sensors corresponding to the wavelength bands. A processing device receives information from the detector and computes spectra therefrom. The second diffraction grating is split spatially or temporally to provide two different responses, so the system can disambiguate spectra. In embodiments, the spectrometer computes hyperspectral images of a target.

Abstract: A measurement apparatus obtains a reference signal from reference light modulated at a first frequency and a measurement signal from measurement light reflected by a target object modulated at a second frequency along with movement of the target object in addition to the modulation at the first frequency, and processes the reference signal and the measurement signal to measure a position of the target object. Synchronized detection units multiply the measurement signal by a signal synchronized with the reference signal and output signals having the second frequency and harmonic components. Decimation filters filter, at a decimation frequency, the signals output from the synchronized detection units to attenuate the harmonic components.

Abstract: Provided is a measuring apparatus that includes a heterodyne interferometer; a first detector configured to detect interference light between reference light and light to be detected, and output a measured signal; a second detector configured to detect interference light between the first and the second light, and output a reference signal; an oscillator configured to generate a standard signal having a frequency corresponding to a frequency shift amount; a first synchronization detector configured to perform synchronous detection of the measured signal and the standard signal; a second synchronization detector configured to perform synchronous detection of the reference signal and the standard signal; a first processing unit that determines a phase difference between the measured signal and the reference signal based on the outputs of the first synchronization detector and the second synchronization detector; and a second processing unit that determines the position of the object based on the phase differenc

Abstract: An improved Optical Coherence Domain Reflectometry (OCDR) system is provided. One embodiment of this OCDR system outputs a detector signal carrying image depth information on multiple modulation frequencies, where each modulation frequency corresponds to a different image depth. The image depth information from the detector signal may be resolved by tuning to the desired modulation frequency. Another system for imaging body tissue uses multiple frequency modulators such that the light beam does not travel from an optical fiber to free space.

Abstract: An inspection system includes optical components for operating the inspection system in an interference fringe imaging mode and a microscope imaging mode. The inspection system further includes at least one optical light source configured to emit a first wavelength of light to operate the inspection system in the interference fringe imaging mode and configure to emit a second wavelength of light to operate the inspection system in the microscope mode. The first wavelength of light is different from the second wavelength of light.

Abstract: An acoustic signal receiving apparatus including: a Fabry-Perot sensor including a Fabry-Perot interferometer configured to convert an acoustic wave into a light intensity signal; a control unit configured to set a first wavelength and a second wavelength; a detecting unit configured to convert light intensities obtained by irradiation of the Fabry-Perot sensor with light from the first light source and the second light source into electric signals; and a signal processing unit configured to acquire a difference between an electric signal corresponding to the first wavelength and an electric signal corresponding to the second wavelength, wherein the control unit is configured to set the first wavelength and the second wavelength so that differential values of reflectivity spectrum of the Fabry-Perot sensor are different at the first wavelength and the second wavelength.

Abstract: Disclosed is a Natural Light Interferometer. The interferometer measures the amplitude and phase distribution of a coherent or incoherent electromagnetic signal, including natural light. In principle, the amplitude and phase distribution of any signal of any wavelength, incoherent or coherent, may be measured using this technique. The corresponding image may be reconstructed as well. The interferometer exploits Fourier transform heterodyne techniques but extends this technology to incoherent signals. The interferometer generates the analyzing signal by exploiting nanotechnology-based signal generation stimulated by the original signal. The Natural Light Interferometer applications include surveillance and reconnaissance; metrology; space-based free-flying, tethered or rigid interferometer arrays; and ground-based sparse interferometer arrays. There is also disclosed a homodyne embodiment of the Natural Light Interferometer that exploits quadrature phase techniques.

Abstract: The light emission analyzing device includes: a first light intensity calculation unit that performs polynomial approximation on a spectroscopic spectrum indicating a light intensity for each wavelength in a container as measured by a spectrometer so as to calculate the light intensity; a second light intensity calculation unit that subtracts, for each wavelength, the light intensity calculated by the first light intensity calculation unit from the light intensity indicated by the spectroscopic spectrum measured by the spectrometer so as to calculate a light intensity corresponding to a bright-line spectrum of a molecule; and a ratio calculation unit that calculates, by using the light intensity calculated by the second light intensity calculation unit, a ratio between (a) a peak value of a molecular spectrum of a first molecule and (b) a peak value of a molecular spectrum of a second molecule.

Abstract: Problems To provide a method for evaluating characteristics of MZ interferometers in an optical modulator having a plurality of MZ interferometers. Means for Solving Problems When an optical modulator includes a plurality of MZ interferometers, the 0-degree component contains a signal derived from an MZ interferometer other than the MZ interferometers for evaluating the characteristic. For this, it is impossible to accurately evaluate the characteristic of the MZ interferometers. The present invention does not use the 0-degree component normally having the highest intensity. That is, the characteristic of the MZ interferometers are evaluated by using a side band intensity of the component other than the 0-degree component.

Abstract: In an embodiment, a dual-etalon cavity-ring-down frequency-comb spectrometer system is described. A broad band light source is split into two beams. One beam travels through a first etalon and a sample under test, while the other beam travels through a second etalon, and the two beams are recombined onto a single detector. If the free spectral ranges (“FSR”) of the two etalons are not identical, the interference pattern at the detector will consist of a series of beat frequencies. By monitoring these beat frequencies, optical frequencies where light is absorbed may be determined.

Abstract: Measuring refractive index of air based on laser synthetic wavelength interferometry. The Apparatus includes a dual-frequency laser that emits orthogonal linear polarized light of wavelengths ?1 and ?2, a beamsplitter, two polarizing beamsplitters, two corner-cube retroreflectors, a quartz vacuum cavity of length L disposed in the measuring optical path in parallel to the light propagation direction, and two detectors. The apparatus is used to measure the refractive index of air using the dual-frequency laser to emit orthogonal linear polarized light with wavelengths ?1 and ?2, using the beamsplitters, corner-cube retroreflectors, quartz vacuum cavity, and detectors. The integer N and fraction ? of interference fringes of wavelength ?2 are determined. The refractive index of air n is obtained by using the length L of the vacuum cavity, integer N and fraction ? of the interference fringes of wavelength ?2.

Abstract: The disclosure relates to a detection device for imaging an object, that comprises: a laser cavity for transmitting an original light signal at an original wavelength towards the object in order to generate an evanescent wave at the surface of the object; a conversion means adapted for converting the evanescent wave into a progressive signal; a re-injection means adapted for injecting the progressive signal into the laser cavity in order to generate interference inside the laser cavity between the progressive signal and the original light signal; a detection means adapted for detecting the interference in order to determine the characteristics of the object; characterized in that the device includes a wavelength modification means adapted so that the wavelength of the progressive signal injected into the laser cavity is different from the original wavelength.

Abstract: A diffuse optical tomography system incorporating a mode-locked, tunable laser produces pulsed light that may be used to interrogate tissue with high spatial and spectral resolution. The detection signal may be heterodyne shifted to lower frequencies to allow easy and accurate measurement of phase and amplitude. Embodiments incorporating wavelength-swept, tunable, lasers and embodiments using broadband photonic fiber lasers with spectrally-sensitive detectors are described.

Abstract: A method and an arrangement are provided for scalable confocal interferometry for distance measurement, for 3-D detection of an object, for Optical Coherence Tomography (OCT) tomography with an object imaging interferometer and at least one light source. The interferometer has an optical path difference not equal to zero at each optically detected object element. Thus, the maxima of a sinusoidal frequency wavelet, associated with each detected object element, each have a frequency difference ?f_Object. At least one spectrally integrally detecting, rastered detector is arranged to record the object. The light source preferably has a frequency comb, and the frequency comb differences ?f_Source are changed in a predefined manner over time in a scan during measuring. In the process, the frequency differences ?f_Source are made equal to the frequency difference ?f_Object or equal to an integer multiple of the frequency differences ?f_Object at least once for each object element.

Abstract: A handheld wavelength meter that includes a housing that encloses a non-stable reference signal source, an interferometer with rotating retroreflectors, optical-electrical converters, a frequency multiplier, and a controller.

Abstract: This disclosure is directed to imaging techniques and image analysis techniques for automated analysis of biological growth media. According to this disclosure, the spectral responses of biological growth media can be used to identify and count biological agents from images of biological growth media. The biological growth media may be illuminated with two or more different wavelengths of electromagnetic radiation, and images of the biological growth media can be captured under these different illuminations. The spectral reflectance values in one or more first images can be normalized based on the spectral reflectance values in one or more second images, wherein the first images are associated with a different wavelength of illumination than the second images. The normalization may allow for better identification of biological agents that manifest on the biological growth media.

Abstract: A Coherent Phased Array Beam Transmission and Imaging System is disclosed for end-to-end compensation of a plurality of laser beams through a turbulent medium to a non-cooperative target where the optical device used to transmit and receive laser energy is a plurality of optical transceivers (typically a telescope, but often referred to as a subaperture telescope or transceiver). The Coherent Phased Array Beam Transmission and Imaging System controls the plurality of laser beams (that originate from a single master oscillator laser and are amplified and/or transported using separate beam paths) to coherently combine the outgoing beams from each subaperture to form a single phased beam at the target. The preferred embodiment for the Coherent Phased Array Beam Transmission and Imaging System includes a method to maintain the beam hit spot on the target aim point at the full resolution of the array.

Abstract: A method of comb-based spectroscopy with synchronous sampling for real-time averaging includes measuring the full complex response of a sample in a configuration analogous to a dispersive Fourier transform spectrometer, infrared time domain spectrometer, or a multiheterodyne laser spectrometer. An alternate configuration of a comb-based spectrometer for rapid, high resolution, high accuracy measurements of an arbitrary cw waveform.

Abstract: The present invention discloses a method and an apparatus for measuring the refractive index of air based on the laser synthetic wavelength interferometry, wherein a laser synthetic wavelength interferometer comprises a dual-frequency laser, a beamsplitter, a first polarizing beamsplitter, a second polarizing beamsplitter, a first corner-cube retroreflector and a second corner-cube retroreflector; a quartz vacuum cavity is disposed in the measuring optical path in parallel to the light propagation direction; when the measurement is performed, air is introduced into the quartz vacuum cavity until it is consistent with outside environment; the variation of the refractive index of air inside the cavity will cause change of the interference signal of the wavelength ?2; the first detector of photoelectric type is used to directly detect the integer N of the interference fringes of the wavelength ?2; then the first corner-cube retroreflector is moved to make the phase difference between the interference signals of

Abstract: An improved Optical Coherence Domain Reflectometry (OCDR) system is provided. One embodiment of this OCDR system outputs a detector signal carrying image depth information on multiple modulation frequencies, where each modulation frequency corresponds to a different image depth. The image depth information from the detector signal may be resolved by tuning to the desired modulation frequency. Another system for imaging body tissue uses multiple frequency modulators such that the light beam does not travel from an optical fiber to free space.

Abstract: Machine-implemented methods and apparatuses to automatically set-up a signal processing system are described. The signal processing system is set to a first bandwidth. A sampling frequency of the signal processing system is set to a first sampling frequency. Next, first samples of first signals are received at the first bandwidth and the first sampling frequency. First parameters of the first signals based on the first samples are determined. Next, a second sampling frequency is determined based on the first parameters to sample second samples. The first parameters of the first signals may be a mean transit time, a minimum transit time, a mean frequency of the signals, and a standard deviation of the frequency of the signals. Next, a mixer frequency is determined based on the first parameters. A low pass filter is set based on the mixer frequency.

Abstract: Provided are a photodetector device and a photodetection method as well as a microscope and an endoscope allowing the heterodyne detection of a desired light to be detected with high sensitivity and at a high SN ratio. A photodetector device comprises a local light emitting unit for generating a local light in temporally unstable interference condition with a light to be detected and a photoelectric conversion unit for generating beat signals between the local light and the light to be detected by photoelectric conversion. The light is detected in heterodyne detection based on an output of the photoelectric conversion unit.

Abstract: The invention relates to a method for coupling a first and second laser (1, 2) having an adjustable difference of their pulse frequencies, which is not equal to zero, wherein the method comprises the following steps: derivation of a first harmonic signal and a signal of the Mth harmonic from the time progression of the light intensity of the pulses emitted by the first laser, mixing of the first harmonic signal and the signal of the Mth harmonic, in order to obtain a first mixed signal, derivation of a second harmonic signal and a signal of the Nth harmonic from the time progression of the light intensity of the pulses emitted by the second laser, mixing of the second harmonic signal and the signal of the Nth harmonic, in order to obtain a second mixed signal, wherein the first and second harmonic signal and the Mth and Nth harmonic are selected in such a manner that the frequencies of the first and second mixed signal are identical, wherein the method furthermore comprises regulation of the pulse frequen

Abstract: A method of and an optical arrangement for generating a non-linear optical signal on a material excited by an excitation field, wherein with the excitation field coherent fields of first and second optical pulses of differing frequency are overlapped in the material in temporal and spatial relationship, wherein the first pulses of a first frequency are generated in a first beam of a first optical generator unit, and the second pulses of a second frequency are generated in a second beam of a second optical generator unit synchronously pumped by the first optical generator unit, wherein with the first pulses of the first frequency as a fundamental frequency pulses of a higher harmonic frequency thereof are generated and the second optical generator unit is pumped with the pulses of the higher harmonic frequency.

Abstract: A heterodyne photomixer spectrometer comprises a receiver photomixer that is driven at a different frequency than the source photomixer, thereby maintaining the coherent nature of the detection, eliminating etalon effects, and providing not only the amplitude but also the phase of the received signal. The heterodyne technique can be applied where the source and receiver elements are components of a waveguide thereby forming an on-chip heterodyne spectrometer.

Abstract: Problems To provide a method for evaluating characteristics of MZ interferometers in an optical modulator having a plurality of MZ interferometers. Means for Solving Problems When an optical modulator includes a plurality of MZ interferometers, the 0-degree component contains a signal derived from an MZ interferometer other than the MZ interferometers for evaluating the characteristic. For this, it is impossible to accurately evaluate the characteristic of the MZ interferometers. The present invention does not use the 0-degree component normally having the highest intensity. That is, the characteristic of the MZ interferometers are evaluated by using a side band intensity of the component other than the 0-degree component.

Abstract: A Scanning Phase Intracavity Nanoscope as a measurement system can be realized with a reference laser cavity and a sample laser cavity superimposed upon each other to operatively propagate two laser beams. The sample laser cavity is operatively formed by the sample to be measured. A measurement of the sample is based on differences in the reference laser cavity and the sample laser cavity determined from difference in the two laser beams.

Abstract: A device for the interferometric measuring of an object, including a light source to generate an emitted beam, a beam splitting device for splitting the emitted beam into a measuring beam and at least first and second reference beams, an optic interference device, and first and second detectors, with the interference device and the first detector being embodied cooperating such that the measuring beam, at least partially reflected by the object, and the first reference beam are interfered on at least one detector area of the first detector. The interference device and the second detector are embodied cooperating such that the measuring beam, at least partially scattered by the object, and the second reference beam are interfered on at least one detector area of the second detector. A method is also provided for the interferometric measuring of an object.

Abstract: Phase differences associated with a defocused wavefront can be determined from a single color image. The color image, which is a measurement of intensity as a function of wavelength, is used to calculate the change in intensity with respect to wavelength over the image plane. The change in intensity can then be used to estimate a phase difference associated with the defocused wavefront using two-dimensional fast Fourier transform solvers. The phase difference can be used to infer information about objects in the path of the defocused wavefront. For example, it can be used to determine an object's shape, surface profile, or refractive index profile. It can also be used to calculate path length differences for actuating adaptive optical systems. Compared to other techniques, deriving phase from defocused color images is faster, simpler, and can be implemented using standard color filters.

Abstract: A multi-wavelength interferometer includes a beam splitter configured to split plural light fluxes into a reference beam and a measurement beam, a frequency shifter configured to shift a frequency of at least one of the reference beam and the measurement beam to make the frequencies of the reference beam and the measurement beam different from each other, an optical system configured to cause the measurement beam to be incident on a measurement surface and to cause the measurement beam reflected from the measurement surface to interfere with the reference beam to obtain interference light, a dividing unit configured to divide the interference light into a plurality of light beams, and a detection unit configured to detect the plurality of light beams divided by the dividing unit.

Abstract: The invention extends classical time-invariant optical design to include optical amplitude modulated light, using tools from communications theory. Effects of dispersion are derived from first principles.

Abstract: This disclosure is directed to information management techniques that may be used during automated processing of biological growth media. In one embodiment, a method comprises reading one or more identification elements of a biological growth medium, identifying manufacturing information related to the biological growth medium based on the one or more identification elements of the biological growth medium, identifying sample information related to a sample being tested by the biological growth medium based on the one or more identification elements of the biological growth medium, generating one or more images of the biological growth medium, counting biological agents formed on the biological growth medium based on the one or more images, wherein counting the biological agents comprises generating a count value, and associating the manufacturing information, the sample information and the count value with the one or more identification elements of the biological growth medium.

Abstract: This disclosure is directed to imaging techniques and image analysis techniques for automated analysis of biological growth media. According to this disclosure, the spectral responses of biological growth media can be used to identify and count biological agents from images of biological growth media. The biological growth media may be illuminated with two or more different wavelengths of electromagnetic radiation, and images of the biological growth media can be captured under these different illuminations. The spectral reflectance values in one or more first images can be normalized based on the spectral reflectance values in one or more second images, wherein the first images are associated with a different wavelength of illumination than the second images. The normalization may allow for better identification of biological agents that manifest on the biological growth media.

Abstract: A measuring apparatus includes an optical frequency comb source configured to emit an optical frequency comb in which a plurality of frequency components are arranged at equal frequency intervals, a beam splitter configured to split a beam emitted from the optical frequency comb source into a test beam to be irradiated onto a test surface and a reference beam to be irradiated onto a reference surface, an optical path difference changing element configured to change an optical path difference between the reference beam and the test beam, an image sensor configured to capture an interference pattern formed by interference between the test beam and the reference beam, and an analyzer configured to calculate a position of the test surface based upon a signal of the interference pattern captured while the optical path length difference is being changed by the optical path difference changing element.

Abstract: The disclosure relates to a cold atom interferometry sensor that includes: a source of atoms; a dual-frequency laser capable of generating a first Raman dual-frequency laser beam; a reflector arranged so as to reflect the first Raman dual-frequency laser beam in order to generate a second Raman dual-frequency laser beam, the first laser beam and the second laser beam propagating in different directions in order to obtain atomic interference fringes from the emission of cold atoms obtained from the atom source; characterized in that the reflector is further arranged so as to enable multiple reflections of the first beam on surfaces of the reflector, so that the first beam and the multiple reflections thereof allow the capture of atoms from the atom source in order to obtain the cold atoms.

Abstract: A broadband blazed array has a plurality of elements. The elements are arranged side-by-side in a non-parallel spaced apart fashion with center-to-center spacing between adjacent elements being identical along cross-sections of the array that are aligned with the array's endfire directions.