Patent attributes
An optical apparatus comprises: a waveguide substrate, optical cladding formed on the substrate; a waveguide core formed within the cladding, an optically absorptive layer formed within the cladding, and a linearly polarized light source. The waveguide core includes an attenuating segment thereof, and the absorptive layer is formed near the attenuating segment of the core. The core and cladding are arranged to form an optical waveguide that supports a propagating optical mode. The absorptive layer is positioned near the attenuating segment of the core so as to spatially overlap a portion of the optical mode. The extent of the overlap results in a designed level of optical loss per unit distance of propagation of a linearly polarized optical signal along the attenuating segment of the optical core in the optical mode without substantial alteration of the polarization state of the optical signal.
