Abstract

We present an all-digital phase meter for precision length measurements using heterodyne laser interferometry. Our phase meter has a phase sensitivity of $3\mathrm{\mu rad}/\sqrt{\mathrm{Hz}}$ at signal frequencies of $1\mathrm{Hz}$ and above. We test the performance of our phase meter in an optical heterodyne interferometric configuration, using an active Sagnac interferometer test bed that is flexible and low noise. We demonstrate more than $70\mathrm{dB}$ of laser frequency noise suppression to achieve an optical phase sensitivity of $5\mathrm{\mu rad}/\sqrt{\mathrm{Hz}}$ and a corresponding displacement sensitivity of $0.5\mathrm{pm}/\sqrt{\mathrm{Hz}}$ at signal frequencies above $10\mathrm{Hz}$. In addition, we demonstrate the ability of our phase meter to follow full fringe signals accurately at $100\mathrm{Hz}$ and to track large signal excursions in excess of ${10}^5$ fringes without cycle slipping. Finally, we demonstrate a cyclic error of $\le 1\mathrm{pm}/\sqrt{\mathrm{Hz}}$, above $10\mathrm{Hz}$.

© 2010 Optical Society of America

Subpicometer length measurement using semiconductor laser tracking frequency gauge

Rajesh Thapa, James D. Phillips, Emanuele Rocco, and Robert D. Reasenberg
Opt. Lett. 36(19) 3759-3761 (2011)

Polarization-based balanced heterodyne detection method in a Sagnac interferometer for precision phase measurement

Ke-Xun Sun, Eric K. Gustafson, M. M. Fejer, and Robert L. Byer
Opt. Lett. 22(17) 1359-1361 (1997)

Balanced heterodyne signal extraction in a postmodulated Sagnac interferometer at low frequency

Ke-Xun Sun, Martin M. Fejer, Eric K. Gustafson, and Robert L. Byer
Opt. Lett. 22(19) 1485-1487 (1997)

Linearization and minimization of cyclic error with heterodyne laser interferometry

Terry G. McRae, Magnus T. L. Hsu, Christopher H. Freund, Daniel A. Shaddock, Jan Herrmann, and Malcolm B. Gray
Opt. Lett. 37(13) 2448-2450 (2012)

Picometer level displacement metrology with digitally enhanced heterodyne interferometry

Glenn de Vine, David S. Rabeling, Bram J. J. Slagmolen, Timothy T-Y. Lam, Sheon Chua, Danielle M. Wuchenich, David E. McClelland, and Daniel A. Shaddock
Opt. Express 17(2) 828-837 (2009)