Patent ID: 7447403

Claim:
An optical device for reflectively diffracting optical signals, comprising: an input port for receiving an optical signal, the optical signal comprising light having wavelengths corresponding to a predetermined set of wavelength channels; an optical medium, the optical medium comprising at least one of a plurality of waveguide layers and being characterised by a thickness, for guiding the optical signal within the optical device; a grating structure disposed at a predetermined location within the optical medium, the grating structure comprising at least one of a plurality of diffractive elements and a plurality of multilayer reflector elements, each of the at least one of the plurality of diffractive elements and the plurality of multilayer reflector elements comprised of a plurality of shallow structures being at least one of on or within the optical medium and characterised by a depth corresponding to less than the thickness of the optical medium; wherein, the grating structure reflectively diffracts light in dependence upon a wavelength such that light having a wavelength corresponding to a first wavelength channel is directed to a first target location of the optical medium.