A matrix switch of an optical waveguide type which has low transmission loss
variations
and includes uniform grooves with a deep vertical cross section is provided. A
switching part for selecting between a light path extending from an input port
of a first set of optical waveguides 111-11m
to an output port of the first set of optical waveguides 111-11m
and a light path extending from an input port of the first set of optical
waveguides 111-11m to an output port of a second
set of optical waveguides 121-12n is arranged
for insertion into a switching groove arranged at each of the intersections of
the first set of optical waveguides 111-11m and
the second set of optical waveguides 121-12n.
Each of the switching grooves is arranged on an imaginary straight line connecting
intersections of the first set of optical waveguides 111-11m
and the second set of optical waveguides 121-12n.
