Abstract

Long-period gratings (LPGs), used for optical filtering, gain flattening, dispersion compensation and sensing, are mode converters in which a waveguide mode is forward coupled into a second mode via grating induced phase matching. Waveguide based LPGs have recently been demonstrated in glasses and polymers and are the basis for highly integrated devices on an optical chip. Chalcogenide glasses (ChG) have generated significant interest due to the high transparency in the near and mid infrared, photosensitivity to visible light and very high Kerr nonlinearity (n₂ up to 1000 x silica). Nonlinear interactions within LPGs are of particular interest for all-optical switching devices though silica fiber demonstrations required kilowatt pulses due to the low n₂. LPGs in ChG rib guides are therefore promising candidates for all-optical switching devices with thresholds orders of magnitudes lower compared to silica based devices.

© 2007 IEEE