Title:
OPTICAL-PHASE-DIFFERENCE MEASURING METHOD
Document Type and Number:
Japanese Patent JPH04161832
Kind Code:
A
Abstract:
PURPOSE:To make it possible to measure the phase difference accurately in a double-beam interferometer by inclining a reference light wave, generating many interference fringes as a carrier, and obtaining the phase difference based on the positions of the maximum bright part and the minimum dark part. CONSTITUTION:The light wave from a laser 2 is split through a beam splitter 4. One beam is reflected from a plane reflecting mirror 5 and passes through a sample 1. The other beam is reflected from a plane reflecting mirror 6 as the reference light and then synthesized and interfered with the light wave which has passed through the sample 1 in a beam splitter 7. The image of the interference fringes is focused on a photodetector 9. The phase is computed in an operating circuit 10. In this constitution, the plane reflecting mirror 6 is inclined by theta, and the phase difference is generated between both light waves. Thus, the interference fringes having the high space frequency are generated as the carrier. The maximum bright part and the minimum dark part of the generated interference fringes are detected, and the phase difference is obtained by the operation in the operating circuit 10.
Inventors:
MATSUZAKI HIROSHI
Application Number:
JP28930690A
Publication Date:
June 05, 1992
Filing Date:
October 26, 1990
Export Citation:
Assignee:
OLYMPUS OPTICAL CO
International Classes:
G01J9/02; G01M11/02; G01N21/45; (IPC1-7): G01J9/02; G01M11/02
Attorney, Agent or Firm:
Taiji Shinohara (1 person outside)