Patent ID: 7167609

Claim:
An optical switch, comprising: an input port on which an optical signal is incident; a plurality of output ports from which an optical signal is outputted; and a plurality of optical waveguides whose output path of an optical signal branches into two, wherein a propagating path of an optical signal incident from the input port is selected to output the optical signal from a desired output port among the output ports, the optical switch further comprising: a first stage optical switch section provided in a branching portion of the optical waveguide where at least two optical waveguides intersect for switching, a propagating path of an optical signal to a path leading to the desired output port; and a subsequent stage optical switch section provided in a branching portion of the optical waveguide where at least two optical waveguides intersect subsequent to the first stage optical switch section for switching a propagating path of a leakage light, which is leaked from the first stage optical switch section, to a path which does not propagates the leakage light to any of the output ports, wherein the input port, the output ports, the optical waveguides, the first stage optical switch section, and the subsequent stage optical switch section are provided on a same substrate, and the first stage optical switch section and the subsequent stage optical switch section switch a path of an optical signal according to a refractive index change caused by a carrier injection.