Development of a highly-stable alignment monitor for a severe environment (2nd report)

Improvement of the interferometer by polarization maintain optics

Abstract

We develop a highly stable alignment monitor which can work in a severe environment of high magnetic field and vacuum by adopting a length measurement grid of optical fiber introduced absolute distance interferometers. At that system, interference signals and consequently free spectral range, FSR of its reference etalon and distances measured by the interferometer are affected by deformations of the optical fibers. Here, we improve uncertainties in their evaluations and measured distances by adopting a polarization maintain optics.