High-Resolution Time-Average Electronic Holography For Vibration Measurement.pdf

ARTICLE IN PRESS
Optics and Lasers in Engineering 41 (2004) 529–535
Photorefractive shearing interferometer
. Cai*, Q. Liu, . Wang, . Yang
Department of Optics, Shandong University, Jinan 250100, People’s Republic of China
Received 6 July 2002; received in revised form 7 November 2002; accepted 10 December 2002
Abstract
A novel method of obtaining shearing interferogram by slightly moving the crystal in a
photorefractive interferometer is proposed. This method can measure the phase of an object
itself instead of its diffraction field, and it is easy to realize continuously changeable shearing
distance in any lateral direction and introduce carrier fringes at the same time. Both the
theoretical analysis and experimental verification are given.
r 2003 Elsevier Science Ltd. All rights reserved.
Keywords: Shearing interferometer; Photorefractive crystals; Optical testing; Aberrations
1. Introduction
Lateral shearing interferometer is an important tool to analyze phase distribution
of an object or the aberrations of ponents [1]. Compared with
conventional interferometric systems such as Twyman–Green and Mach–Zehnder
interferometers, shearing interferometer is much less sensitive to the imperfections of
optical systems and the environment disturbance owing to the same or almost the
same optical path of the two waves to pared. Therefore, it is widely