Optical Review

, 15:276

Common-path double-pass optical interferometry using a wire-grid polarizer as a reference mirror

Regular Papers


A novel common-path double-pass optical interferometer that employs a wire-grid polarizer (WGP) as a reference mirror is presented. When a laser beam polarized at 45° relative to the wire grid is incident on the WGP, the polarization component parallel to the grid direction (s-polarized beam) is reflected and is used as a reference beam. The perpendicular component (p-polarized beam) passes through the WGP coupled with a quarter-wave plate and serves as a probe beam, with its polarization transformed as p, right-circular, s, left-circular, and p, to irradiate the sample surface twice in order to double the phase change due to displacement of the sample. This beam is then retransmitted through the WGP, where it recombines and interferes with the reference beam. Preliminary experiments demonstrate that the WGP performs successfully as a reference mirror, and that the interferometer has a potential displacement sensitivity as low as 0.1 nm.

Key words

optical interferometer common-path double-pass wire-grid polarizer reference mirror displacement sensitivity 

Copyright information

© The Optical Society of Japan 2008

Authors and Affiliations

  1. 1.Production Engineering Research LaboratoryHitachi Ltd.YokohamaJapan

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