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Title: Apparatus and method for performing two-frequency interferometry

Abstract

The present apparatus includes a two-frequency, Zeeman Effect laser and matched, doubly refracting crystals in the construction of an accurate interferometer. Unlike other interferometric devices, the subject invention exhibits excellent phase stability owing to the use of single piece means for producing parallel interferometer arms, making the interferometer relatively insensitive to thermal and mechanical instabilities. Interferometers respond to differences in optical path length between their two arms. Unlike many interferometric techniques, which require the measurement of the location of interference fringes in a brightly illuminated background, the present invention permits the determination of the optical path length difference by measuring the phase of an electronic sine wave. The present apparatus is demonstrated as a differential thermooptic spectrometer for measuring differential optical absorption simply and accurately which is but one of many applications therefor. The relative intensities of the heating beams along each arm of the interferometer can be easily adjusted by observing a zero phase difference with identical samples when this condition is obtained. 6 figs.

Inventors:
Issue Date:
Research Org.:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
OSTI Identifier:
6283807
Patent Number(s):
7147468
Application Number:
ON: DE89010895
Assignee:
Dept. of Energy
Patent Classifications (CPCs):
A - HUMAN NECESSITIES A61 - MEDICAL OR VETERINARY SCIENCE A61C - DENTISTRY
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; INTERFEROMETERS; DESIGN; INVENTIONS; LASERS; OPTICAL PROPERTIES; OPTICAL SPECTROMETERS; ZEEMAN EFFECT; MEASURING INSTRUMENTS; PHYSICAL PROPERTIES; SPECTROMETERS; 440300* - Miscellaneous Instruments- (-1989)

Citation Formats

Johnston, R. G. Apparatus and method for performing two-frequency interferometry. United States: N. p., 1988. Web.
Johnston, R. G. Apparatus and method for performing two-frequency interferometry. United States.
Johnston, R. G. Mon . "Apparatus and method for performing two-frequency interferometry". United States. https://www.osti.gov/servlets/purl/6283807.
@article{osti_6283807,
title = {Apparatus and method for performing two-frequency interferometry},
author = {Johnston, R. G.},
abstractNote = {The present apparatus includes a two-frequency, Zeeman Effect laser and matched, doubly refracting crystals in the construction of an accurate interferometer. Unlike other interferometric devices, the subject invention exhibits excellent phase stability owing to the use of single piece means for producing parallel interferometer arms, making the interferometer relatively insensitive to thermal and mechanical instabilities. Interferometers respond to differences in optical path length between their two arms. Unlike many interferometric techniques, which require the measurement of the location of interference fringes in a brightly illuminated background, the present invention permits the determination of the optical path length difference by measuring the phase of an electronic sine wave. The present apparatus is demonstrated as a differential thermooptic spectrometer for measuring differential optical absorption simply and accurately which is but one of many applications therefor. The relative intensities of the heating beams along each arm of the interferometer can be easily adjusted by observing a zero phase difference with identical samples when this condition is obtained. 6 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 25 00:00:00 EST 1988},
month = {Mon Jan 25 00:00:00 EST 1988}
}