Abstract:
We disclose apparatus that includes: (a) an enclosure including an aperture; (b) a prism mounted in the enclosure so that a surface of the prism is exposed through the aperture; (c) an optical assembly contained within the enclosure, the optical assembly including a radiation source and a radiation detector, the source being configured to direct radiation towards the prism and the detector being configured to detect radiation from the source reflected from the exposed surface of the prism; and (d) an electronic processor contained within the enclosure, the electronic processor being in communication with the detector. The apparatus can be configured so that, during operation, the electronic processor determines information about a sample placed in contact with the exposed surface of the prism based on radiation reflected from the exposed prism surface while it is in contact with the sample.
Abstract:
An imaging optical system includes a set of mirrors including at least three mirrors on a beam path. Only a last mirror on the beam path has a positive optical power and all other mirrors have negative optical power. The sum of the optical powers of the mirrors is zero. An external posterior aperture stop is on the beam path between the last mirror and the image plane. A back focal length of the optical system is equal to or greater than an effective focal length of the optical system. The field of view is large, and typically at least 30-40 degrees in one plane.
Abstract:
In a spectrometer, preferably in a spectrometric microscope, input light is provided from a light source to a specimen via a source objective element (e.g., a Schwarzchild objective), and the aperture of the light source is matched to the aperture of the source objective element to maximize light throughput to the specimen. The light from the specimen is then collected at a collector objective element and delivered to a camera element, which in turn provides the light to a photosensitive detector. The apertures of the camera element and the collector objective element are also matched to maximize light throughput from the specimen to the detector. As a result, light loss from vignetting effects is reduced, improving the intensity and uniformity of illumination and the sensitivity and accuracy of spectral measurements.
Abstract:
In a spectrometer, preferably in a spectrometric microscope, input light is provided from a light source to a specimen via a source objective element (e.g., a Schwarzchild objective), and the aperture of the light source is matched to the aperture of the source objective element to maximize light throughput to the specimen. The light from the specimen is then collected at a collector objective element and delivered to a camera element, which in turn provides the light to a photosensitive detector. The apertures of the camera element and the collector objective element are also matched to maximize light throughput from the specimen to the detector. As a result, light loss from vignetting effects is reduced, improving the intensity and uniformity of illumination and the sensitivity and accuracy of spectral measurements.
Abstract:
In a spectrometer, preferably in a spectrometric microscope, light from a specimen is collected at a collector objective element and delivered to a camera element, which in turn provides the light to a photosensitive detector. A focal plane is provided between the collector objective element and the camera element, and one or more aperture arrays may be situated in the focal plane to restrict the detector's field of view of the specimen to the areas within the apertures. By utilizing aperture arrays with apertures of different sizes and shapes, the spatial resolution of the spectrometer readings may be varied without the need to vary the optics of the spectrometer. As a result, if the optics are optimized to minimize vignetting, spatial resolution may be varied without adverse increases in vignetting.
Abstract:
A spectroscopic method and system for the spectral analysis of an optical signal directed to a wavelength dispersive component having two interleaved dispersive devices. For a single wavelength, the optical signal exiting the interleaved dispersive devices includes two wavefronts generally disposed at an angle to one another and producing an interference pattern. The interference pattern is detected and subsequently analyzed via a Fourier transform to produce the optical spectrum of the input beam. The method and system are applicable in a planar waveguide environment, in reflection and transmission geometries.
Abstract:
A catch side optical system for use in diode laser spectroscopy consisting of a catch side optic optically coupled to a catch side multimode optical fiber and means to mechanically manipulate a section of the catch side multimode optical fiber to minimize catch side mode noise. The mechanical manipulation may consist of twisting the catch side multimode optical fiber around its longitudinal axis. The means to mechanically manipulate the section of the catch side multimode optical fiber in the above fashion may consist of a motor associated with the catch side multimode optical fiber such that a section of fiber is held fast relative to a shaft position of the motor and the motor shaft is repetitively swept through +360 degrees and −360 degrees of motion. The frequency of the motor shaft sweep may be at least 10 Hz to enable effective averaging of the transmitted signal and thereby reduce the effect of catch side mode noise.
Abstract:
A sensing apparatus consisting of more than one diode laser having select lasing frequencies, a multiplexer optically coupled to the outputs of the diode lasers with the multiplexer being further optically coupled to a pitch side optical fiber. Multiplexed laser light is transmitted through the pitch side optical fiber to a pitch optic operatively associated with a process chamber which may be a combustion chamber or the boiler of a coal or gas fired power plant. The pitch optic is oriented to project multiplexed laser output through the process chamber. Also operatively oriented with the process chamber is a catch optic in optical communication with the pitch optic to receive the multiplexed laser output projected through the process chamber. The catch optic is optically coupled to an optical fiber which transmits the multiplexed laser output to a demultiplexer. The demultiplexer demultiplexes the laser light and optically couples the select lasing frequencies of light to a detector with the detector being sensitive to one of the select lasing frequencies.
Abstract:
A spectroscope includes an optical fiber 218, a collimator optical system 231 for collimating signal light come out from the optical fiber 218, a spectroscopic element 233 for dispersing the signal light collimated by the collimator optical system 231, a detector 237 composed of a plurality of detector elements 237a disposed at least in a direction of dispersion and detecting the light dispersed by the spectroscopic element 233, and a focusing optical system 236 for focusing the signal light come out from the detector 237 onto a detecting surface of the detector 237. It is set such that the focusing optical system 236 makes a diameter of a spot of the signal light focused on the detecting surface of the detector 237 smaller than an arranged pitch of the detector 237 and a numerical aperture of the collimator optical system 231 is larger than that of the optical fiber 218.
Abstract:
A spectrophotometric instrument is comprised of a processor, a probe having a tissue engaging surface with an aperture therethrough and a light source producing measurement light signals and optically coupled to the probe via a first optical path. A partially reflective first reflecting member is located in the probe and has a generally elliptical profile positioned to reflect a first portion of the measurement light signals to the tissue aperture and to transmit a second portion of the measurement light signals through the first reflecting member. A second reflecting member is located in the probe and has a generally elliptical profile positioned to reflect the measurement light signals transmitted through the first reflecting member. A second optical path has a distal end positioned to receive the measurement light signals reflected off of the second reflecting member and a proximal end coupled to the processor. A third optical path has a distal end positioned in the probe to receive light signals transmitted through the tissue sample and a proximal end coupled to the processor.