Patent ID: 7826700

Claim:
An optical device, comprising: a light-transmitting medium defining a sensing portion of a waveguide and also defining a non-sensing portion of the waveguide such that the light transmitting medium extends from the non-sensing portion of the waveguide into the sensing portion of the waveguide, the light-transmitting medium that defines the sensing portion of the waveguide including a light-absorptive region where the light-transmitting medium includes defects that provide the light-absorptive region with a deep band gap level between a valence band of the light-transmitting medium and a conduction band of the light-transmitting medium, the deep band gap level configured such that the waveguide guiding light signals through the light-transmitting medium in the sensing portion causes free carriers to be generated in the light-transmitting medium, the light transmitting medium that defines the non-sensing portion of the waveguide excluding the light-absorptive, and the waveguide being configured to guide the light signals such that an optical mode of the light signals partially overlaps the absorptive region; and a detector configured to detect the free carriers in the sensing portion of the waveguide.