<title>Test apparatus of distributed polarization coupling in fiber gyro coils using white light interferometry</title>

An account is given of a novel instrument that employs white-light interferometry to determine the spatial distribution of parasitic polarization coupling along as much as 1 km of high-birefringence optical fiber. This device is directly applicable to test-gyro coils in which localized spurious coupling points are able to affect bias stability. The required measurement time is of the order of 1 min for 1 km of fiber.