Accession Number : ADD006705

Title :   Laser Interferometer Probe.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Hesselink,Lambertus

Report Date : 23 Oct 1979

Pagination or Media Count : 6

Abstract : Index of refraction measurements are made by means of an optical device in which a coherent light beam is divided into an object beam and a reference beam, each of which is directed through a separate path in a common light transmitting medium. The object beam is also transmitted en route through a test volume that accommodates a substance to be tested. It is subsequently recombined with the reference beam to form a single output beam. The output beam is received by a photo detector and its intensity is measured. The intensity of the detected output beam is related to any phase shift between the object and reference beams. The phase shift in turn is a measure of the index of refraction of the test substance. Information relating to density, temperature and pressure of the test substance can be derived from measured index of refraction values by using conventional conversion formulas. An operating range control is provided by introducing a volume of pressurized gas into the paths of the object and reference beams. The operating range of the instrument is set by adjusting the pressure of the gas in the absence of a test substance. (Author)

Descriptors :   *Patents, *Optical interferometers, *Interferometry, Laser beams, Refractive index, Phase shift, Probes(Electromagnetic)

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE