Accession Number:

AD0165021

Title:

Optical Film Thickness Monitor.

Descriptive Note:

Patent,

Corporate Author:

DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s):

Report Date:

1973-07-10

Pagination or Media Count:

5.0

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.

Subject Categories:

  • Test Facilities, Equipment and Methods
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE