A lateral shearing interferometer with variable shearing for measurement of a small beam is proposed. The interferometer is composed of a polarization beam splitter, a thick birefringent plate, a quarter-wave plate, a mirror, and an image sensor. The shearing amount can be tiny by using the thick birefringent plate as the shear generator. The shearing amount of the interferometer can be continuously adjusted by rotating the thick birefringent plate, and 2D interferograms can be obtained by rotating the thick birefringent plate along the mutually perpendicular directions. The optical path difference is compensated with a double lateral shearing by using a quarter-wave plate and a mirror. The interferometer is verified by simulation and experiment; the experiment result is well coincident with the simulation result. The usefulness of the interferometer is verified.
© 2014 Optical Society of America
Original Manuscript: January 8, 2014
Revised Manuscript: February 25, 2014
Manuscript Accepted: February 26, 2014
Published: March 25, 2014
Lei Liu, Aijun Zeng, Linglin Zhu, and Huijie Huang, "Lateral shearing interferometer with variable shearing for measurement of a small beam," Opt. Lett. 39, 1992-1995 (2014)