Optical switching system and devices using a long period grating

摘要

The present invention provides an optical switching system for use with an optical fiber that has a core of a prescribed refractive index and a cladding and that is configured to carry an optical signal of a prescribed bandwidth. Preferably, the optical fiber's core includes a photosensitive dopant. In a preferred embodiment, the optical switching system comprises an optical switch coupled to the optical fiber and includes a grating within the core. The optical switch has selectable non-diverting and forward-diverting modes of operation wherein the optical switch alters the prescribed refractive index: to render the grating substantially transparent to the optical signal as the optical switch operates in the non-diverting mode or, alternatively, to allow the grating to divert at least a portion of the optical signal forward and into the cladding as the optical switch operates in the forward-diverting mode. The grating rating preferably has a periodicity that increases a sensitivity of the grating to changes in the refractive index.