A wavelength selective switch device is disclosed that includes an
elongated signal communication path extending from a first end of the
device to a second end of the device. The signal communication path
extends through a plurality of regions of varying indices of refraction,
and the plurality of regions includes adjustable regions that are each
coupled to an adjustable voltage source for changing a voltage potential
across each of the adjustable regions such that the index of refraction
of said adjustable regions may be changed by changing the voltage
potential across each adjustable region.