Abstract:
An object of the invention is to realize an optical spectrum analyzer capable of performing high-speed waveform sweep. The invention is to make improvements to an optical spectrum analyzer for measuring a spectrum of light to be measured by collimating light to be measured by collimator means, spectroscopically separating the collimated light incident from the collimator means according to an incident angle by a diffraction grating, and detecting the light spectroscopically separated by the diffraction grating by a photodetector via a slit. The device is characterized by including an acoustooptic deflector provided between the collimator means and the diffraction grating for deflecting the collimated light to be measured and changing the incident angle on the diffraction grating.
Abstract:
Fluorescence emitted from a tissue can be detected efficiently, and excitation light with a plurality of wavelengths can be simultaneously emitted to simultaneously detect fluorescence with a plurality of wavelengths. A laser-scanning fluoroscopy apparatus includes a laser light source of a plurality of wavelengths; a spectroscopic device for splitting laser beams according to wavelength; a focusing lens for focusing the split laser beams; and a wavelength-selecting reflection device which includes a plurality of reflection sections disposed near the focal positions, spaced out at predetermined intervals in a split direction to reflect the laser beams with different wavelengths and a transmission section arranged adjacent to the reflection sections. The laser-scanning fluoroscopy apparatus further includes a diffraction grating for combining the reflected laser beams; a scanning section for two-dimensionally scanning the combined laser beams; an objective optical system for focusing the scanned laser beams onto a tissue; and a photodetector for detecting fluorescence emitted from the tissue. A width dimension, as measured along the split direction, of each reflection section of the wavelength-selecting reflection device is smaller than a width dimension of the transmission section.
Abstract:
A spectrometer that provides the ability to combine the advantages of high resolution, compactness, ruggedness, and low-power consumption of Fabry-Perot (FP) tunable filter spectrometer, with the multi-channel multiplexing advantage of FT and/or grating/detector array. The key concept is to design and operate a tunable FP filter in a multiple-order condition. This filter is then followed by a “low-resolution” fixed grating, which disperses the filtered n-order signal into a preferably matched N-element detector array for parallel detection. The spectral resolution in this system is determined by the FP filter, which can be designed to have very high resolution. The N-order parallel detection scheme reduces the total integration or scan time by a factor of N to achieve the same signal to noise ratio (SNR) at the same resolution as the single channel tunable filter method. This design is also very flexible, allowing spectrometer systems with appropriate order N to thereby optimize the system performance for spectral resolution and scan integration time. In addition to the significant reduction in scan integration time, there are two other advantages to this approach. The first, because the FP tunable filter is designed and operated under n-orders, the fabrication tolerances of the FP filter cavity and operating conditions are significantly loosened.
Abstract:
A scanning tunable detection system and related method for analyzing samples includes a source of time varying excitation signals and a tunable optical filter for selectively transmitting time-varying optical signals emanated from a sample following irradiation with the time varying excitation signals. A detector is provided for converting the time-varying optical signals to electrical detection signals. The system can identify components in a sample using phase sensitive or time sensitive detection. A slew scan mode can be used to permit slow scanning through spectral regions rich in information but quickly in regions without such information.
Abstract:
Optical instruments having, inter alia, optics to process wavelengths of electromagnetic radiation to produce an interferogram. The instruments include at least one optical path and optical elements positioned along this path for splitting the electromagnetic radiation and spectrally dispersing the wavelengths to produce first and second sets of spectrally dispersed beams which interfere with each other to produce a plurality of different fringes of different wavelengths. The optics for dispersing the wavelengths includes a matched pair of gratings. The gratings may be reflective or they may be transmissive. The optics also includes a beam splitter and first and second mirrors. The gratings may be positioned in a variety of locations along the optical path. The instruments can also include a detector for detecting the interferogram and means for processing the detected interferogram to produce spectral information.
Abstract:
A method for spectral analysis of the light proceeding from a specimen using a multi-band detector comprises the steps of defining an overall spectral region; from the overall spectral region, defining a first spectral subregion and defining at least a second spectral subregion; simultaneously detecting the light proceeding from the specimen in the first and the second spectral subregion, and generating detection values; displacing the first spectral subregion and displacing the second spectral subregion within the overall spectral region; and repeating steps c) and d) until the light has been detected over the entire overall spectral region.
Abstract:
An optical channel monitor (OCM) or filter for analyzing an incident light carrying a number of narrow band signal channels such as WDM or DWDM channels. The OCM or filter use an acousto-optic tunable filter to receive and refract from an incident light a refracted light such that the refracted light contains a test channel with a center frequency &ngr;0. A first birefringent element is provided for filtering from the refracted light a first polarized light and a second polarized light orthogonal to the first polarized light. The transmission curves are engineered such that the transmissions of the first and second polarized light are substantially equal at the center frequency &ngr;0 of the test channel. The OCM or filter has a second birefringent element for filtering from the first polarized light a first polarized portion and a second polarized portion. The transmission curves of the second birefringent element are set such that the transmissions of the first and second polarized portions are substantially equal at a first offset &dgr;1&ngr; from the center frequency &ngr;0.
Abstract:
A method of in situ analysis of a biological sample comprising the steps of (a) staining the biological sample with N stains of which a first stain is selected from the group consisting of a first immunohistochemical stain, a first histological stain and a first DNA ploidy stain, and a second stain is selected from the group consisting of a second immunohistochemical stain, a second histological stain and a second DNA ploidy stain, with provisions that N is an integer greater than three and further that (i) if the first stain is the first immunohistochemical stain then the second stain is either the second histological stain or the second DNA ploidy stain; (ii) if the first stain is the first histological stain then the second stain is either the second immunohistochemical stain or the second DNA ploidy stain; whereas (iii) if the first stain is the first DNA ploidy stain then the second stain is either the second immunohistochemical stain or the second histological stain; and (b) using a spectral data collection device for collecting spectral data from the biological sample, the spectral data collection device and the N stains are selected such that a spectral component associated with each of the N stains is collectable.
Abstract:
A fluorescent in situ hybridization method comprising the steps of (a) providing a cell nuclei having chromosomes hybridized with at least one nucleic acid probe including at least one nucleic acid molecule labeled with at least one fluorophore; (b) viewing the cell nuclei through a fluorescence microscope optically connected to an imaging spectrometer for obtaining a spectrum of each pixel of the cell nuclei by (i) collecting incident collimated light simultaneously from all pixels of the cell nuclei; (ii) passing the incident collimated light through an interferometer system so that the light is first split into two coherent beams and then recombine to interfere and form an exiting light beam; (iii) focusing the exiting light beam on a detector having an array of detector elements, so that at each instant each of the elements is the image of one and always the same pixel for the entire duration of the measurement and so that each of the elements produces a signal which is a particular linear combination of light intensity emitted by the pixel at different wavelengths; (iv) rotating or translating one or more of the elements of the interferometer, so that the optical path difference is scanned simultaneously for all the pixels of the cell nuclei; and (v) recording signals of each of the detector elements as function of time using a recording device to form a first spectral cube of data; and (c) interpreting the first spectral cube of data using a mathematical algorithm.
Abstract:
A solid state moisture gauge is disclosed in which a quartz-halogen bulb is used with an acousto-optic tunable filter to launch light of specific desired wavelengths into a parallel plate cavity device which contains or is adjacent to material having a moisture content which is to be measured. The light exiting from the parallel plate device is detected, converted to a digital signal and then stored in a computer for later comparison to the detection of light exiting from the parallel plate device of a different wavelength.