Kilometric optical fiber interferometer

We report on a preliminary experimental study of an interferometer built with two 500 meters long arms made of polarization maintaining optical fibers. The control of the field polarization state along the single-mode fiber arms enables to measure fringe contrast up to 93% with a laser source emitting a 1290nm carrier wavelength. Tests achieved with broadband spectrum exhibit dispersion differential effect resulting from fiber inhomogeneities. Partial compensation of this effect is achieved introducing additional fiber pieces on one arm. (C) 2001 Optical Society of America.