We present a new approach to processing of interferometric data, which dramatically improves operation on the smallest fraction of the fringe (~1/1000 of a wavelength and beyond). In particular, this approach, dubbed the variation-invariant subspace tracking approach (VISTA), makes it possible to operate a Michelson interferometer in a highly stable mode in which the estimation of optical path delay becomes invariant (insensitive) to a large class of systematic model errors. This previously unknown invariance property of interferometry follows from the fundamental odd–even symmetry of the channeled spectrum and its derivatives. VISTA offers a powerful algorithmic alternative for alleviating technological challenges in the design of high-precision long-baseline spaceborne interferometers.
© 2001 Optical Society of America
Valeri I. Karlov, Carlos E. Padilla, Keto Soosaar, Leslie E. Matson, Hon M. Chun, and Glenn V. Webb, "High-precision fringe tracking invariant to systematic model errors," J. Opt. Soc. Am. A 18, 2565-2576 (2001)