P. Paolino and L. Bellon, Optics Communication 280 1-9 (2007)
doi: 10.1016/j.optcom.2007.07.060
We present an application of a quadrature phase interferometer to the measurement of the angular position of a parallel laser beam with interferometric precision. In our experimental realization we reach a resolution of 6.8e-10 rad (1.4e-4 arcsec) for 1 kHz bandwidth in a 2e-2 rad (1 deg) range. This alternative to the optical lever technique features absolute calibration, independence of the sensitivity on the thermal drifts, and wide range of measurement at full accuracy.