Abstract: A system is described for determining the phase relationship between two coherent beams and, if the beams are not in phase, providing a correction signal to bring them into phase. The system combines the beams to create an interference fringe pattern, the pattern exhibiting, if the beams are in phase, a central peak (zero order) irradiance fringe bounded on either side by lesser peak (higher order) irradiance fringes. The fringe pattern responds to a change in the relative phase of the beams by the fringes walking to the left or right under the stationary modulation envelope depending upon the direction of phase change between the beams. A pair of side fringe detectors are positioned to detect the lesser peak irradiance fringes but not the central peak irradiance fringe and to provide signals indicative of the power in each lesser peak irradiance fringe. A processor responsive to those signals, provides a correction output when the signals indicate unequal powers.

Abstract: A high optical efficiency dual spectra pyrometer for measuring the temperature of a target includes an optical guide for collecting and guiding a target optical beam to a detection module which comprises an interference filter and photodetectors adjustably positioned to provide efficient coupling of the target optical beam thereto. The pyrometer additionally includes a signal processor which receives the signals from the photodetectors, as well as signals indicative of an estimated fireball equivalent black body temperature and the spectral width difference between the two detector signals, and provides a compensated temperature signal.

Abstract: High gloss titanium dioxide pigment slurries are prepared by using the underflow from the thickener, optionally treated with aluminum oxide, plus an organic dispersant, plus optionally a polyol.