A new instrument for measuring small angles by use of multiple total internal reflections in heterodyne interferometry is presented. With this instrument we can achieve a small rotation angle only by measuring the variation in phase difference between s- and p-polarization states. To improve its sensitivity we increase the number of total internal reflections by using two parallelogram prisms instead of two right-angle prisms. The angular resolution of the new instrument is better than 2.2 × 10-6 rad over the measurement range -2.12° ≤ θ ≤ 2.12° for 20 total-internal reflections. The experimental results and the theoretical curve are in good agreement.
© 2004 Optical Society of America
(040.2840) Detectors : Heterodyne
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(260.6970) Physical optics : Total internal reflection
Ming-Hung Chiu, Shinn-Fwu Wang, and Rong-Seng Chang, "Instrument for Measuring Small Angles by Use of Multiple Total Internal Reflections in Heterodyne Interferometry," Appl. Opt. 43, 5438-5442 (2004)