  We have observed a large (~1%) change in infrared reflectance of the
charge-density-wave (CDW) conductor, orthorhombic TaS3, when its CDW is
depinned. The change is concentrated near one current contact. Assuming that
the change in reflectance is proportional to the degree of CDW polarization, we
have studied the dynamics of CDW repolarization through position dependent
measurements of the variation of the electro-reflectance with the frequency of
square wave voltages applied to the sample, and have found that the response
could be characterized as a damped harmonic oscillator with a distribution of
relaxation (i.e. damping) times. The average relaxation time, which increases
away from the contacts, varies with applied voltage as t0 ~ 1/V^p with p ~ 3/2,
but the distribution of times broadens as the voltage approaches the depinning
threshold. Very low resonant frequencies (~ 1 kHz) indicate a surprisingly
large amount of inertia, which is observable in the time dependence of the
change in reflectance as a polarity dependent delay of ~ 100 microsec.
