Abstract: Ice in particular and also other substances such as water and glycol-containing anti-icing fluids can be detected and distinguished by means of differences in their optical index of refraction. A plurality of beams at different angles of incidence are multiplexed onto the reverse side of an optical surface which is embedded in a surface to be monitored or otherwise positioned in a sampling environment. The reflected beams at the different angles are measured and refractive indexes calulated form the measured reflected beams. If the calculated refractive indexes are the same at all angles, then the substance is positively identified. If the values do not agree, then there is partial coverage, and the substance may be identified by comparison with predetermined values. The system is applicable to aircraft, where in-flight and pre-flight monitoring of icing conditions and surface contamination is needed.

Abstract: Apparatus is disclosed for pre-determining laser coagulation dosages and for monitoring laser photocoagulation during treatment by detection of radiation produced in the eye. Embodiments of the present invention comprise means for applying radiation to a target in an eye (1, 2, 3, 5, 6, 7 and 9) and means for detecting the radiation produced by the target having wavelengths different from the wavelength of the applied radiation (4, 200, 12 and 13). In various embodiments, the radiation produced by the target is fluorescence radiation, Raman radiation, two photon excitation radiation and so forth.

Abstract: A fluorometer system is disclosed in which a carousel-like system is rotated by a stepper motor to provide a sequence of sample wells to a single optical exciting path. An ultraviolet tube positioned adjacent that path provides an excitation beam which is reflected into common optical path which coincides with the position of the well along the common path is deflected by a beam splitter or the like through an appropriate filtering device to a photomultiplier tube which is located adjacent the common light path on the same side of the path as the ultraviolet tube. The photomultiplier tube is located below the ultraviolet tube to provide a proper direction of convection current.Further, a solid state photosensor sensitive in red spectrum such as a phototransistor or photodiode is provided adjacent the ultraviolet tube, with a ruby positioned between the ultraviolet tube and the photosensor the take advantage of the fact that solid-state photosensors are especially responsive to light in the red range.