Dynamically Controllable Bragg Gratings

This book emphasizes on the realization,
investigation and manipulation of Bragg gratings
with external electrical control especially for
spectral filtering applications. Volume
photorefractive Bragg gratings realized in bulk
lithium niobate crystals are manipulated with
external electric field in order to demonstrate fast
electrically switchable holographic lenses and
mirrors. Furthermore, photorefractive Bragg gratings
are inscribed in lithium niobate waveguides and a
fast electrically tunable integrated optical
spectral filter is demonstrated. The most important
and interesting part is the
introduced concept of phase-shift keying of
corrugated waveguide Bragg gratings which was used
to dynamically reconfigure the Filter transfer
function. This novel concept comprises, for the
first time to the best of author's knowledge, the
use of external electric field to dynamically
inscribe phase-shifts to more than two sections of
the already fabricated integrated corrugated Bragg
grating. Employing this technique, a fast ( one
microsecond) reconfiguration or synthesis of the
transfer function into several desirable profiles is
demonstrated.