Abstract:
Spectrophotometric apparatus and methodology suitable for continuous and long-term use. The apparatus includes a monochromator (13) providing pre-dispersed monochromatic light to the optical inputs of a pair of fiber optic cables (34-37) and a translator (43) for alternatively positioning the fiber optic cables (34-37) at the same location with respect to the monochromator output. One of the cables (61) conducts light to a sample under study while the other cable (35b) provides a reference for light intensity measurements. The methodology includes the steps of performing two scans through the monochromator output for each measurement on the sample. The fiber optic cables are moved between scans so that the cable employed in the latter scan occupies the former position of the cable employed in prior scan.
Abstract:
A fixed grating, detector-array type analyzer (100) rapidly multiplexes multiple channels. The analyzer (100) comprises a light source (110), a detector array-type spectrograph (150) and an optical multiplexer (130). The multiplexer (130) can select from one of a plurality of channels. Further, the multiplexer (130) can convolute light passing through it with a reference spectrum for calibration and wavelength drift compensation. Rapid multiplexing is achieved using a fiber optic slit array (140) which ''perpendicularly multiplexes'' the plurality of channels.
Abstract:
The installation has an inlet slot (5) of a spectrometer with a photoelectric receiver arranged at its outlet (7) as well as a polarization prism (4) so arranged that the beam is divided into two parts (2, 3) of which the polarization planes are mutually perpendicular, the separation being effected in the direction of the longitudinal axis of the inlet slot (5). Between the polarization prism (4) and the inlet slot (5) in a location where the beams (2, 3) are separated, there is provided a manoeuvrable shutter (9) which alternatingly allows either one or the other of the beams (2, 3) to pass.
Abstract:
A microscope accessory uses symmetrical pairs of identical parabolic mirrors (5, 6) as an imaging optic to map a specimen plane with a remote focus. A mask (24) at the remote focus defines at least one measuring area for making spectroscopic measurements while a separate viewing system simultaneously provides a wide field of view of the sample at higher magnification. The sample aperture, defined as the 2 steradians of solid angle surrounding each side of the specimen plane, is multiplexed between and among different functions - such as spectroscopic measurements and visual observations. The high numerical aperture possible using identical symmetrical aberration canceling (ISAC) optics facilitates the aperture multiplexing which has particular advantage in making reflectance measurements without any need for a significant loss of throughput efficiency or resolution and in raman microspectroscopy.
Abstract:
Spectroscopic apparatus for carrying out sample analysis in which means (6, 7, 8) is provided for generating a plurality of beams of radiant energy, at least one of which forms a reference beam and at least one other forms a sample beam, A radiation detector (4) is arranged to receive each beam successively and is energized by a power source (12) operable to apply any one of a plurality of controlling energy levels (e.g. stabilized voltages) to the radiation detector. The apparatus is calibrated by applying the/or each sample beam to the energized detector and selecting a voltage level for that energization such that the output of the detector is substantially the same as that obtained for all other beams and particularly the reference beam. The apparatus further includes coupling means (15) which, during normal use of the apparatus, causes application of a respective voltage level to the detector according to which beam impinges on that detector.