Patent ID: 7190858

Claim:
An apparatus, comprising: a first optical waveguide substantially confining in one transverse dimension an optical signal propagating in two dimensions therein, the first optical waveguide having a first set of diffractive elements configured and positioned for routing at least a portion of an optical signal propagating in the optical waveguide between an input optical port and a switch input optical port; an optical source positioned for launching an optical signal into the optical waveguide through the input optical port; a 1×N optical switch connecting the switch input optical port to any one of N switch output optical ports based on a selected operational state of the 1×N optical switch; and a second optical waveguide substantially confining in one transverse dimension an optical signal received from any of the N switch output optical ports and propagating in two dimensions therein, the second optical waveguide having N additional sets of diffractive elements, each set of the N additional sets of diffractive elements corresponding to one of the N switch output optical ports and being configured and positioned for routing at least a portion of an optical signal received from the corresponding one of the N switch output optical ports to an output optical port, wherein: the first diffractive element set is adapted for imparting a wavelength-dependent optical delay onto the routed portion of the optical signal; the N additional diffractive element sets and the output optical port are positioned relative to the switch output optical ports so that each corresponding optical pathlength between each of the switch output optical ports and the output optical port varies among the switch output optical ports; an optical signal at only a selected one of multiple optical source wavelengths reaches the output optical port based on a selected operational state of the optical source; and optical propagation time delay between the input optical port and the corresponding output optical port varies according to the selected operational state of the 1×N optical switch and according to the selected operational state of the optical source.