Abstract: A counting signal processing method for a fiber optic interferometric sensor including following steps is provided. An output intensity of the fiber optical interferometric sensor is converted into an electrical signal having the form V0+V1 cos ?(t). Then, the number of times N1 that the maximum peak values are greater than a first counting level S1 and the number of times N2 that the minimum peak values are smaller than a second counting level S2 within a specific period of time TC are counted. When the value of N1, N2 or (N1+N2) is greater than a threshold counting number Cth, a detectable induced signal occurring in a sensing area is inferred. Then, whether the detectable induced signals are caused by an intruder or otherwise is judged through an alarm identification logic, and an alarm device is triggered to send out an alarm according to the result of the judgment.

Abstract: A light source system includes a beam source generating a first input beam of light. An anisotropic acousto-optic modulator (AOM) is positioned to receive the first input beam. The AOM includes a plurality of transducers for receiving control signals and generating corresponding acoustic waves that operate on the first input beam to generate first and second output beams with different frequencies and orthogonal linear polarizations. The first and second output beams have a combined optical power that is substantially the same as an optical power of the first input beam for a first input beam with one polarization and for a first input beam with two polarizations.

Abstract: The light intensity ratio adjustment filter is placed between the reference surface and the sample surface of the interferometer. This light intensity ratio adjustment filter has a light intensity ratio adjustment film including an optical reflection-absorption layer and a dielectric anti-reflection layer on the surface of a transparent substrate made of glass on the sample side, and an optical anti-reflection film on the reference surface side, and acts so as to reflect part of the incident light from the surface opposite the reference surface, and after absorbing part of the remaining light, transmit the remainder towards the sample, and furthermore, absorb part of the light returned from the sample while controlling reflection, and transmit the remainder in the direction of the reference surface as the sample light.

Abstract: In general, in one aspect, the invention features methods that include interferometrically monitoring a distance between an interferometry assembly and a measurement object along each of three different measurement axes while moving the measurement object relative to the interferometry assembly. The methods also include monitoring an orientation angle of the measurement object with respect to a rotation axis non-parallel to the three different measurement axes while the measurement object is moving, determining values of a parameter for different positions of the measurement object from the monitored distances, wherein for a given position the parameter is based on the distances of the measurement object along each of the three different measurement axes at the given position, and deriving information about a surface figure profile of the measurement object from a frequency transform of at least the parameter values.

Abstract: An optical tomographic apparatus is provided and includes a light source portion, an interferometer, and a signal processing portion. The light source portion including two low coherent light sources capable of simultaneously emitting light having wavelength bands different from each other. The emitted light is divided in two of a light flux irradiated to a subject by a probe and a light flux irradiated to reference mirrors that is divided by a dichroic mirror into light fluxes for respective wavelength bands. The reference light from the reference mirrors is combined with detected light from the subject to provide interference light. An optical detector detects the interference light for respective wavelength bands by a spectroscopic optical system, and a signal processing portion processes the detected light to provide optical tomographic images with regard to different portions of the subject for respective wavelength bands.

Abstract: Process control monitors are disclosed that are produced using at least some of the same process steps used to manufacture a MEMS device. Analysis of the process control monitors can provide information regarding properties of the MEMS device and components or sub-components in the device. This information can be used to identify errors in processing or to optimize the MEMS device. In some embodiments, analysis of the process control monitors may utilize optical measurements.

Abstract: Measurement of sample surface flatness of a continuously moving sample. A conveyor continuously conveys a sample beneath a grating disposed at a non-zero angle with respect to the plane of conveyance. The relative distance between the sample and the angled grating changes with the horizontal translation of the sample. A camera disposed above the sample and the grating captures, at constant time intervals, a sequence of images, each image comprising a shadow moiré fringe pattern that is indicative of the sample's surface flatness. The continuous change in relative distance between the sample and the grating introduces a known or unknown phase step between the shadow moiré fringe patterns of each successive image. A computer associated with the camera processes the images to determine phase values of pixels at, and the relative height of the sample surface at, selected pixel locations of the sample.

Abstract: The present invention provides a method to detect and generate ultrasonic displacements at a remote target for ultrasonic inspection. This method involves generating an ultrasonic wave at a first location on an upper surface of the remote target. This ultrasonic wave is reflected from interior surfaces within the remote target wherein the reflected ultrasonic wave produces ultrasonic displacement at a second location on the upper surface of the remote target. A detection laser beam is generated and directed to the second location on the upper surface of the remote target. Here, the detection laser beam is scattered by the ultrasonic displacements to produce phase-modulated light. This phase-modulated light is collected and processed to obtain data representative of the ultrasonic surface displacements. Further, these ultrasonic displacements, when processed, will yield inspection information associated with the interior of the remote target.

Abstract: Apparatus and methods for adjusting the polarizations of the components of an input beam to reduce leakage caused by imperfections in an interferometer are disclosed. The apparatus includes an interferometer positioned to receive an input beam that includes two components having different frequencies and different polarizations, the interferometer including a polarizing beam splitter positioned to spatially separate the input beam into two intermediate beams, the first intermediate beam corresponding to the first component and the second intermediate beam corresponding to the second component, where imperfections in the interferometer cause leakage of one of the components into the intermediate beam corresponding to the other of the components. The apparatus further includes a polarization compensator that includes at least one retardation plate positioned to adjust the polarizations of the components of the input beam to reduce the leakage caused by the imperfections in the interferometer.

Abstract: An image data set acquired by an optical coherence tomography (OCT) system is corrected for effects due to motion of the sample. A first set of A-scans is acquired within a time short enough to avoid any significant motion of the sample. A second more extensive set of A-scans is acquired over an overlapping region on the sample. Significant sample motion may occur during acquisition of the second set. A-scans from the first set are matched with A-scans from the second set, based on similarity between the longitudinal optical scattering profiles they contain. Such matched pairs of A-scans are likely to correspond to the same region in the sample. Comparison of the OCT scanner coordinates that produced each A-scan in a matching pair, in conjunction with any shift in the longitudinal scattering profiles between the pair of A-scans, reveals the displacement of the sample between acquisition of the first and second A-scans in the pair.

Abstract: Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code.

Abstract: Disclosed is an optical sensing device, which comprises a light source emitting a light; a beam splitter; an SPR sensor unit comprising a sensing surface; and a detecting mechanism; and a converting unit converting the first beam and the second beam from the optical device into a two-dimensional interference fringe pattern. From the above-mentioned configuration, an extra phase shift of a detection beam in SPR phase measurement is obtained. The differential measurement approach has shown to achieve a sensitivity figure significantly better than the best result that can be obtained from the prior art in the field of the measurement based on an SPR sensor.

Abstract: An interferometer system includes an optical radiation source, an optical circulator connected between the optical radiation source and a sample location for transmitting optical radiation from the optical radiation source to the sample location, an output of the optical circulator connected to direct optical radiation to an optical detector. Various embodiments of such a system are possible. A method of performing OCDR or OCT imaging of a sample which involves the steps of: (a) producing low coherence optical radiation; (b) directing at least some of the low coherence optical radiation through an optical circulator to the sample; (c) reflecting at least some of the low coherence optical radiation off of the sample; and (d) detecting at least some of the reflected low coherence optical radiation and producing an electrical signal corresponding thereto.

Abstract: A method and apparatus that uses specific source modulation and detectors to detect a response that carries information about a system response matrix associated with each sensor in a interferometric sensor array and extracting a sensor response in a manner that eliminates polarization-induced signal fading and that is insensitive to lead fiber birefringence fluctuations.

Abstract: An imaging system for imaging an object point to an image point, the system including: a beam splitter positioned to receive light rays from the object point and separate each of a plurality of rays into a transmitted portion and a reflected portion, the transmitted portions defining a first set of rays and the reflected portions defining a second set of rays; and an array of independently positionable reflecting elements forming a reflecting surface positioned to receive one of the sets of rays from the beam splitter and focus that set of rays towards the image point via the beam splitter.

Abstract: Apparatus, method, logic arrangement and storage medium are provided for increasing the sensitivity in the detection of optical coherence tomography and low coherence interferometry (“LCI”) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies. The LCI broad bandwidth source can be split into N spectral bands. The N spectral bands can be individually detected and processed to provide an increase in the signal-to-noise ratio by a factor of N. Each spectral band may be detected by a separate photo detector and amplified. For each spectral band, the signal can be band p3 filtered around the signal band by analog electronics and digitized, or, alternatively, the signal may be digitized and band pass filtered in software. As a consequence, the shot noise contribution to the signal is likely reduced by a factor equal to the number of spectral bands, while the signal amplitude can remain the same.

Abstract: An optical apparatus may include a plurality of Fabry-Perot cavities and a controller. The plurality of Fabry-Perot cavities receives an incoming image. The controller controls a group of adjacent Fabry-Perot cavities of the plurality of Fabry-Perot cavities to sample spectral information from a pixel of the incoming image. The group maybe designated to the pixel. Sizes of the cavities within the group may differ from one another. The sizes of the cavities within the group may be fixed during the spectral information synthesis operation.

Abstract: Embodiments of the present disclosure provide systems and methods for constructing a profile of sample object. Briefly described, in architecture, one embodiment of the system, among others, can be implemented as follows. An interferometer device is used to collect interference images of a sample object at a sequence of angles around the sample object. Accordingly, a controller device rotates the sample object to enable acquisition of the interference images; and a projection generator produces projections of the sample object from the interference images at the sequence of angles. Further, a tomographic device constructs the profile of the optical device from the projections of the interference images. The profile is capable of characterizing small index variations of less than 1×10?4. Other systems and methods are also included.

Abstract: The invention relates to a device for remote measurement of the properties of the atmosphere, more particularly a device used to detect atmospheric turbulence. The device operates on the lidar principle, using the backscattering of a laser beam by the air. The device comprises a laser emission source (1), optical means (5) for collecting a backscattered beam (3) that is backscattered by targets illuminated by the emission source (1), the backscattered beam (3) being substantially centerd about the wavelength of the emission source (1), and means (9) for generating interference fringes (24) resulting from the backscattered beam (3). The device also includes a spatial filter (11) allowing only a central spot of the interference fringes to be seen and, at the center of the spatial filter (11), a mask for blocking off the center of the central spot and more particularly the Mie line of the backscattered beam.

Abstract: Quantum resonance fluorescent microscope systems for detecting component substances in a specimen are described. The systems are based on exciting the sample containing the material with a femtosecond to nanosecond probe pulse of collimated light, which is tailored to optimize detection of a given material by separating the probe pulse into component features of frequency, polarization, phase and/or amplitude. The component features are independently shaped and formed into a composite pulse selected to optimize a signature response pulse received from the material. In some cases, two independently re-shaped pulses are combined, where one re-shaped pulse has two mixed polarization states and the other re-shaped pulse is linearly polarized. These two pulses are made to intersect at an angle of 90 degrees so that the combined pulse has electric field in each of the XYZ axes.