Patent ID: 6175671
Filing Date: 2001-01-16
Classification: B82Y,G02B,G02F,H01S

Abstract:
A waveguide device for an optical signal comprising;a slab of dielectric medium;a latticed region formed in the dielectric medium by a periodic array of lattice sites comprising localised structures having dielectric properties which are different from those of the surrounding medium, the periodic array being dimensioned such that a photonic bandgap exists in the latticed region inhibiting propagation of the optical signal therethrough; anda waveguide region formed in the dielectric medium by discontinuities in the periodic array of lattice sites allowing propagation of the signal therethrough;wherein the waveguide region defines an input region for the input of the optical signal, an output region for the output of the optical signal and a plurality of optical pathways for conducting respective components of the optical signal between the input and output regions;wherein the waveguide region defines a cavity bounded by a boundary surface at the transition between the latticed region and the waveguide region, the cavity communicating with the input region and the output region; andwherein the boundary surface constitutes a plurality of reflectors directing respective components of the optical signal via said respective optical pathways between the input region and the output region.