A reflective optical switch for use in optical systems, such as fiber
optic communications networks, is disclosed. The optical switch includes
not only signal transmission characteristics, but also signal reflection
capability. The optical switch includes a semiconductor substrate having
first and second optical signal waveguides disposed thereon. The two
waveguides intersect one another at a selected angle to form an
intersection region. A thermal element is disposed atop the intersection
region and can be activated to alter the index of refraction of a portion
of the intersection region. An optical signal passing through the
intersection region is diverted from one waveguide to another according
to the heating of the intersection region by the thermal element. A
reflective component disposed in a terminal end of one of the waveguides
reflects selected optical signals back to the source from which they
came.