A waveguide type liquid-crystal optical switch including: an optical waveguide
having a pair of first and second cores close to each other for switching an optical
path between the pair of first and second cores; a third core made of nematic liquid
crystal enclosed in between a pair of oriented films and oriented in a predetermined
direction by the pair of oriented films, the third core being disposed in any one
of a space covering the first and second cores in parallel with a plane containing
optical axes of the first and second cores, a space sandwiched between the first
and second cores and a space covering upper surfaces of the first and second cores
so as to be laid over the first and second cores; a first electrode disposed on
a surface of the third core opposite to the first and second cores so as to cover
a gap portion between the first and second cores; second and third electrodes disposed
as a pair, between which electrodes the first electrode is put, the second and
third electrodes provided for orienting liquid crystal molecules in a direction
perpendicular to the direction of orientation of the oriented films; and a clad
for collectively surrounding the first, second and third cores and the first, second
and third electrodes.
