Phase shifting diffraction interferometer
Abstract
An interferometer which has the capability of measuring optical elements and systems with an accuracy of .lambda./1000 where .lambda. is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about .lambda./50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms.
- Inventors:
-
- Santa Cruz, CA
- Issue Date:
- Research Org.:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- OSTI Identifier:
- 870577
- Patent Number(s):
- 5548403
- Assignee:
- Regents of University of California (Oakland, CA)
- Patent Classifications (CPCs):
-
G - PHYSICS G01 - MEASURING G01B - MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS
G - PHYSICS G01 - MEASURING G01J - MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- phase; shifting; diffraction; interferometer; capability; measuring; optical; elements; systems; accuracy; lambda; 1000; wavelength; visible; light; current; interferometers; employ; reference; surface; inherently; limits; measurement; 50; essentially; perfect; spherical; wavefront; generated; fundamental; process; adjustable; unity; fringe; visibility; maximizes; signal-to-noise; means; introduce; controlled; prescribed; relative; shift; optics; permits; analysis; interference; pattern; standard; extraction; algorithms; measuring optical; reference surface; relative phase; diffraction interferometer; phase shifting; phase shift; optical element; optical elements; visible light; fringe pattern; spherical reference; reference wavefront; reference wave; interference fringe; essentially perfect; shifting diffraction; phase extraction; current interferometers; interferometers employ; /356/
Citation Formats
Sommargren, Gary E. Phase shifting diffraction interferometer. United States: N. p., 1996.
Web.
Sommargren, Gary E. Phase shifting diffraction interferometer. United States.
Sommargren, Gary E. Mon .
"Phase shifting diffraction interferometer". United States. https://www.osti.gov/servlets/purl/870577.
@article{osti_870577,
title = {Phase shifting diffraction interferometer},
author = {Sommargren, Gary E},
abstractNote = {An interferometer which has the capability of measuring optical elements and systems with an accuracy of .lambda./1000 where .lambda. is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about .lambda./50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 1996},
month = {Mon Jan 01 00:00:00 EST 1996}
}