Patent ID: 7376311

Claim:
An optical apparatus for receiving a multi-wave input optical signal comprising: a first planar lightwave circuit (PLC) including: a single input/output waveguide for receiving the multi-wavelength input optical signal, and for outputting one or more output optical signals, a first waveguide array having a first waveguide coupler, a second waveguide coupler and at least two waveguides optically connecting the first and second couplers, wherein the first coupler is physically connected, and directly coupled optically without intervention, to the input/output waveguide, and wherein said first array exhibits a free-spectral range equal to the channel separation of the input optical signal, and introduces a first dispersion into the input optical signal, a second waveguide array including an input waveguide coupler, wherein the input coupler is physically connected, and directly coupled optically without intervention, to the second coupler of the first waveguide array, and wherein the second waveguide array has a plurality of waveguides terminating at an edge facet of the PLC, and exhibits a free-spectral range equal to all of the channels of the input optical signal, and produces a second dispersion into the input optical signal which adds to the first dispersion; a lens adjacent to the PLC; and an optical receiving unit adjacent to the lens; wherein the edge facet of the PLC and the optical receiving unit are respectively positioned at a front focal plane and a back focal plane of the lens such that an input optical signal is propagated through the PLC to generate a phased array output at the edge facet of the PLC, the phased array output is spatially Fourier transformed by the lens to generate a spectrally resolved image having a discrete or somewhat discrete light spot for each channel or band of channels of the input optical signal on to the optical receiving unit.