G01N2021/4742

Fiber optic bolometer

The present disclosure is directed to a fiber optic bolometer device. In an implementation, a fiber optic bolometer device includes an optical fiber and a silicon layer that comprises a Fabry-Prot interferometer. The silicon layer includes a first surface and a second surface. The fiber optic bolometer device includes a reflective dielectric film disposed over the first surface of the silicon layer where the reflective dielectric film is adjacent to an end face of the optical fiber. The fiber optic bolometer device also includes an absorptive coating disposed over the second surface of the silicon layer (e.g., the surface distal to the end face of the optical fiber).

Image acquiring apparatus, systems, and methods
10357160 · 2019-07-23 · ·

Two-dimensional image acquiring apparatuses, systems, methods and storage mediums are provided herein. An apparatus includes a Spectrally Encoded Endoscopy (SEE) probe including a diffractive element, the diffractive element operating to separate and diffract a transmitted light into separated light beams such that the diffracted light beams are superposed or substantially superposed on a target region; an image sensor that operates to acquire one or more intensities from a detected light; and an imaging optical system that operates to image light beams separated from the detected light, wherein the diffractive element, the imaging optical system, and the sensor are disposed for each of the light beams separated from the detected light to acquire spectral data of each of the light beams separated from the detected light. The diffractive element operates to rotate such that an image of the image sensor is changed, and a two-dimensional image is acquired.

Non-linear frequency scan optical frequency-domain reflectometry having a processor to estimate a backscattering profile of an optical fiber by applying a predefined function to a beat signal

A system (20) for fiber-optic reflectometry includes an optical source (28, 40), a beat detection module (44, 48, 52, 56A, 56B) and a processor (36). The optical source is configured to generate a non-linearly-scanning optical interrogation signal having an instantaneous optical frequency that is a non-linear function of time. The beat detection module is configured to transmit the optical interrogation signal into an optical fiber (24), to receive from the optical fiber an optical backscattering signal in response to the optical interrogation signal, and to mix the optical backscattering signal with a reference replica of the optical interrogation signal, so as to produce a beat signal. The processor is configured (i) to hold a predefined function that is indicative of an expected phase of the beat signal resulting from the non-linearly-scanning optical interrogation signal as a function of position along the optical fiber and time, (ii) to estimate a backscattering profile of the optical fiber by applying the predefined function to the beat signal, and (iii) to sense one or more events affecting the optical fiber by analyzing the backscattering profile.

MEASURING APPARATUS AND METHOD FOR ROUGHNESS AND/OR DEFECT MEASUREMENT ON A SURFACE

A measuring apparatus has at least two radiation sources arranged to illuminate a measuring region of a surface of a sample, the at least two sources configured to illuminate the measuring region along at least two illumination beam paths at different angles of incidence relative to a surface normal of the surface, a detector device configured to detect at least two scattered radiation images of surface sections in the illuminated measuring region at a predetermined viewing angle relative to the surface normal of the surface, portions of the scattered radiation received by the detector device, which portions are formed in each case by the illumination in one of the illumination beam paths, in each case having a common spatial frequency, and an evaluation device configured to determine at least one roughness feature of the surface sections from the at least two scattered radiation images.

COLOR IMAGING BY DISCRETE NARROW-BAND SYNCHRONIZED ILLUMINATION
20190154569 · 2019-05-23 ·

A color imaging system and method, the method comprising, for a plurality of predetermined wavelength bands of illumination, calculating weight coefficients representing the contribution of each of the wavelength bands to a specific color space, individually controlling illumination intervals of each of a plurality of illumination sources, wherein each of the illumination sources is configured to provide illumination via a waveguide in a different predetermined narrow band of wavelengths, controlling an image sensor to capture a set of monochromatic image frames synchronously with the illumination intervals, receiving a set of the captured monochromatic image frames, and generating color image data by calculating a combination of the set of image frames, each weighted by the corresponding coefficient.

Method and apparatus for OCT-based viscometry

Methods and apparatus for ascertaining a relative viscosity characterizing a fluid sample. The fluid sample is illuminated through a scattering membrane adjacent to the fluid with broadband radiation. Scattering from particles within the fluid sample characterized by a distribution of characteristic dimensions spanning at least two orders of magnitude is detected, generating a detector signal as a function of depth relative to a specified surface of the scattering membrane at a plurality of temporal delays. A cross-correlation function of at least one of amplitude, phase and intensity of a scattered optical field is derived for a plurality of depths relative to the specified surface. A mean cross-correlation function is then derived for each depth and fit to obtain a diffusion coefficient, from which a relative viscosity characterizing the fluid is derived.

IMAGE ACQUIRING APPARATUS, SYSTEMS, AND METHODS
20190104941 · 2019-04-11 ·

Two-dimensional image acquiring apparatuses, systems, methods and storage mediums are provided herein. An apparatus includes a Spectrally Encoded Endoscopy (SEE) probe including a diffractive element, the diffractive element operating to separate and diffract a transmitted light into separated light beams such that the diffracted light beams are superposed or substantially superposed on a target region; an image sensor that operates to acquire one or more intensities from a detected light; and an imaging optical system that operates to image light beams separated from the detected light, wherein the diffractive element, the imaging optical system, and the sensor are disposed for each of the light beams separated from the detected light to acquire spectral data of each of the light beams separated from the detected light. The diffractive element operates to rotate such that an image of the image sensor is changed, and a two-dimensional image is acquired.

Power limiting methods for use with optical systems in hazardous area locations

A fiber optic sensor interrogation system with inbuilt passive power limiting capability that provides improved safety performance for use in explosive atmospheres.

Optical sensor having fiduciary marks detected by backscattered light
10234385 · 2019-03-19 · ·

An optical fiber having at least one fiduciary mark is provided. The at least one fiduciary mark is located at one or more axial positions along the optical fiber. The at least one fiduciary mark is configured to produce at least one change in a backscattering signal in the optical fiber. The at least one change in a backscattering signal may be an abrupt change in the backscattering signal. The abrupt change in the backscattering signal occurs over a length of the optical fiber that is of the order of or less than a spatial resolution of an interrogation system employed to detect the backscattering signal.

Particle detection apparatus

There is provided a particle detection apparatus (30) comprising: a channel (32) including an inlet and at least one channel wall, the inlet permitting light to be introduced into the channel (32), the or each channel wall being arranged to define a channel path through which light may propagate; a light source (34) configured to introduce light into the channel (32) via the inlet, the channel (32) being shaped to guide the light to propagate along the channel path for illuminating a particle or a plurality of particles located in the channel path; and a monitoring device (36) configured to detect scattered light that is created by the illumination of the or each particle by the guided light and that leaves the channel (32) by passing through the or each channel wall.