Abstract:
An imaging system for providing spectrographically resolved images. The system incorporates a one-dimensional spatial encoding mask which enables an image to be projected onto a two-dimensional image detector after spectral dispersion of the image. The dimension of the image which is lost due to spectral dispersion on the two-dimensional detector is recovered through employing a reverse transform based on presenting a multiplicity of different spatial encoding patterns to the image. The system is especially adapted for detecting Raman scattering of monochromatic light transmitted through or reflected from physical samples. Preferably, spatial encoding is achieved through the use of Hadamard mask which selectively transmits or blocks portions of the image from the sample being evaluated.
Abstract:
Spectral analysis of a beam of radiation is carried out by splitting the beam of radiation into its respective spectral components and by applying a characteristic modulation to each of the spectral components before allowing them to fall on a common detector. The super-imposed signals generated by the detector and representative of the spectral components are then electronically segregated by reference to the characteristic modulations that have been applied to the individual spectral components. This is conveniently done by generating a series of modulated reference signals which have been modulated in exactly the same way as the spectral components of interest. The technique is not restricted to optical spectra but can also be used, for example, for X-ray spectra and mass spectra.
Abstract:
An interchangeable encoding cassette and a spectrometer system employing such cassette, which cassette device encodes the spectral energy of radiation at the exit focal plane of a spectrometer, the spectral energy represented by horizontal and vertical components. The cassette device comprises a rotating encoding disc, a stationary aperture plate, a frame element, and a shaft secured to the encoding disc for rotation therewith. The frame includes bearings on which the shaft is mounted and includes a reference pin. The spectrometer includes a pair of locater mounts, each of which has a precision V groove adapted to receive the shoulders of the bearing element of the cassette, one of such locators having an adjustable track adapted to receive the pin element, whereby the shaft serves as a primary reference and the cassette device is adjusted into the desired precision position by the position of the reference pin in the restraining track.
Abstract:
A radiation gate or window for a spectrometer, in which two such gates are relatively rotatable at the input and output ends of a ray path traversing a dispersive system, has a multiplicity of zones of different conveying characteristics (transparent and opaque or reflective) forming a plurality of identical sets which are mutually transposed, by an angle representing an aliquot fraction of a circle, with reference to a common center. In one embodiment the zones are bounded by identical, angularly offset spirals originating at the center of rotation, the spacing between adjacent spirals diminishing progressively with increasing distance from the center.