Accession Number : AD0165021
Title : Optical Film Thickness Monitor.
Descriptive Note : Patent,
Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C
Personal Author(s) : Bey,Paul B. ; Patten,Raymond A.
Report Date : 10 JUL 1973
Pagination or Media Count : 5
Abstract : The patent describes an apparatus for measuring the optical thickness of a thin film on a substrate by using two light beams of different wavelengths. The beams are chopped into a series of time-alternating pulses, passed through the film and substrate and detected to provide an electrical pulse output. Alternate pulses are then subtracted from each other and the differences are averaged. A null occurs whenever the optical film thickness is at integral quarter-wavelengths of the average wavelength of the two light beams.
Descriptors : *Optical coatings, *Thickness, *Optical instruments, *Patents, Instrumentation, Thin films, Monochromators
Subject Categories : Test Facilities, Equipment and Methods
Distribution Statement : APPROVED FOR PUBLIC RELEASE