The sensitivity to input polarization in long-cavity (1 cm to 5 m) and
high-finesse (similar to 100) fiber Fabry-Perot interferometers (FFPI
's) is reduced from greater than 20 dB to between 0.2 and 0.6 dB in pa
ssband amplitude variation by the use of very-low-birefringence fibers
. Furthermore the scanning FFPI's could allow very-high-resolution mea
surement of polarization-mode dispersion in short-length low-birefring
ence fibers.