Abstract: A technique for high sensitivity evanescent field molecular sensing employs a detection scheme that simultaneously couples a polarized beam to a single mode of a waveguide, and couples the polarized beam out of the waveguide to specularly reflect the beam by the same grating. Strong interaction with the single (preferably TM) mode is provided by using a silicon on insulator (SOI) wafer having a waveguide thickness chosen between 10-400 nm so that the majority of the mode field strength spans the evanescent field. Well known, robust techniques for producing a grating on the waveguide are provided. Interrogation from a backside of the SOI wafer is taught.

Abstract: A technique for high sensitivity evanescent field molecular sensing employs a detection scheme that simultaneously couples a polarized beam to a single mode of a waveguide, and couples the polarized beam out of the waveguide to specularly reflect the beam by the same grating. Strong interaction with the single (preferably TM) mode is provided by using a silicon on insulator (SOI) wafer having a waveguide thickness chosen between 10-400 nm so that the majority of the mode field strength spans the evanescent field. Well known, robust techniques for producing a grating on the waveguide are provided. Interrogation from a backside of the SOI wafer is taught.

Abstract: An interface device for performing mode transformation in optical waveguides includes an optical waveguide core for propagating light of a particular wavelength or a plurality of wavelengths. The optical waveguide core terminates in a subwavelength grating configured to change the propagation mode of the light. The subwavelength grating has a pitch sufficiently less than the wavelength of the light to frustrate diffraction. The device can thus serve as an optical coupler between different propagating media, or as an anti-reflective or high reflectivity device.

Abstract: An interface device for performing mode transformation in optical waveguides includes an optical waveguide core for propagating light of a particular wavelength or a plurality of wavelengths. The optical waveguide core terminates in a subwavelength grating configured to change the propagation mode of the light. The subwavelength grating has a pitch sufficiently less than the wavelength of the light to frustrate diffraction. The device can thus serve as an optical coupler between different propagating media, or as an anti-reflective or high reflectivity device.

Abstract: An interface device for performing mode transformation in optical waveguides includes an optical waveguide core for propagating light of a particular wavelength. The optical waveguide core terminates in a subwavelength grating configured to change the propagation mode of the light. The subwavelength grating has a pitch sufficiently less than the wavelength of the light to frustrate diffraction. The device can thus serve as an optical coupler between different propagating media, or as an anti-reflective or high reflectivity device.