Abstract: A method of measuring the extinction of light in a coating including the steps of: directing a light beam to a substrate to be coated at an angle of incidence for which the beam undergoes nominal total internal reflection; depositing a coating on the substrate such that the light beam will be waveguided in the coating thus reducing internal reflection for a period of deposition time; measuring a reduction of the internal reflection during deposition; and calculating an extinction value of the light beam in the deposited layer corresponding to the measured drop in internal reflection.

Abstract: An optical device to reduce the thermally induced distortion and thermally induced depolarization of light transmitted through all or part of the device. The device includes a nominally transparent element having a negative dn/dT and a nominally transparent element having a zero or negative stress optic coefficient.

Abstract: A method and apparatus for cleaning, detecting, and/or removing contamination from the surfaces of nominally transparent materials utilizing internal illumination of those surfaces with at least one electromagnetic radiation beam at an angle of incidence equal to or greater than the critical angle for total internal reflection. With appropriate selection of light sources and materials, the technique is effective at detecting and removing water, ice, particles, films and a variety of contaminants.

Abstract: A beam steerer/scanner (50) includes a dynamically balanced bi-index rotating element (52). The element is comprised of a pair (52A, 52B) of transparent hemispheres which are of the same size and shape, are made from two materials of equal density, but which materials have different refractive indices (n). When the element is oscillated or rotated, an incident beam (L) impinging upon the element through a coupling lens (56) is deviated from its initial path and a deviated beam (T) is emitted from the element through another coupling lens (58). Because the two materials forming the hemispheres are of equal density, the resulting assembly may be oscillated or rotated at very high speeds without causing excessive vibration or stress. The steerer/scanner provides a high (>0.95) throughput and scanning rates as high as 1 kHz are possible. A two-dimensional scanning unit can also be constructed using the same components as used to produce a one-dimensional scanner.