Near-infrared tunable lasers with polymer waveguide Bragg gratings.

Wavelength tunable lasers operating at near infrared (NIR) wavelength are demonstrated through the thermo-optic (TO) refractive index tuning of polymer waveguide Bragg reflectors. The polymer-waveguide device has superior TO efficiency for substantially changing the refractive index, and it enables direct tuning of the Bragg reflection wavelength over a wide range. The waveguide is optimized for NIR wavelengths, and a third-order Bragg reflector is incorporated for facilitating fabrication of the grating.

Ultra-low inter-channel crosstalk in array waveguide device incorporating self-assembled microsphere diffraction layer.

In array-type optical devices integrated on a single chip with high density, the crosstalk between adjacent devices causes main reason of limited transmission capacity in cascaded optical communication systems. In order to reduce the crosstalk in an arrayed variable optical attenuator, we incorporated a self-assembled monolayer of a microsphere array in the device. The microsphere array introduces a large index contrast in the polymer waveguide, thereby causing strong diffraction of the planar guided modes toward the surface normal directions.