An inteprated optical receiver circuit provided on a common substrate, suitable for polarization multiplexed differential quadrature phase-shift keying, comprising: a polarization beam splitter (112,) configured to receive a plurality of first optical signals and a plurality of second optical signals, each of the plurality first of optical signals having a first polarization and a corresponding one of a plurality of wavelengths, each of the second plurality of optical signals having a second polarization and a corresponding one of the plurality of wavelengths, the polarization beam splitter having a first output and a second output, the first output supplying the plurality of first optical signals and the second output supplying the second plurality of optical signals, further comprising, a first arrayed waveguide grating optical demultiplexer having an input and a plurality of outputs, the input of the first optical demultiplexer being configured to receive the plurality of first optical signals, and supply each of the plurality of outputs at a corresponding one of the plurality of outputs of the first optical demultiplexer; a second arrayed waveguide grating optical demultiplexer having an input and a plurality of outputs, the input of the second optical demultiplexer being configured to receive the second plurality of optical signals, and supply each of the plurality of outputs at a corresponding one of the plurality of outputs of the second optical demultiplexer; a first plurality of optical power splitters, each of which being configured to receive a corresponding one of the plurality of first optical signals output from the first optical demultiplexer, and output a plurality of first optical signal portions and a plurality of second optical signal portions; a first plurality of optical delay interferometer circuits, each of which being configured to receive the plurality of first optical signals portions and supply a corresponding one of a plurality of delayed first optical signal portions, each of the plurality of delayed first optical signal portions being delayed relative to a corresponding one of the plurality of second optical signal portions; a second plurality of optical power splitters, each of which being configured to receive a corresponding one of the plurality of second optical signals output from the second optical demultiplexer, and output a plurality of third optical signal portions and a plurality of fourth optical signal portions; and a second plurality of optical delay interferometer circuits, each of which being configured to receive the plurality of third optical signals portions and supply a corresponding one of a plurality of delayed third optical signal portions, each of the plurality of delayed third optical signal portions being delayed relative to a corresponding one of the plurality of fourth optical signal portions. a polarization beam splitter (112,) configured to receive a plurality of first optical signals and a plurality of second optical signals, each of the plurality first of optical signals having a first polarization and a corresponding one of a plurality of wavelengths, each of the second plurality of optical signals having a second polarization and a corresponding one of the plurality of wavelengths, the polarization beam splitter having a first output and a second output, the first output supplying the plurality of first optical signals and the second output supplying the second plurality of optical signals, further comprising, a first arrayed waveguide grating optical demultiplexer having an input and a plurality of outputs, the input of the first optical demultiplexer being configured to receive the plurality of first optical signals, and supply each of the plurality of outputs at a corresponding one of the plurality of outputs of the first optical demultiplexer; a second arrayed waveguide grating optical demultiplexer having an input and a plurality of outputs, the input of the second optical demultiplexer being configured to receive the second plurality of optical signals, and supply each of the plurality of outputs at a corresponding one of the plurality of outputs of the second optical demultiplexer; a first plurality of optical power splitters, each of which being configured to receive a corresponding one of the plurality of first optical signals output from the first optical demultiplexer, and output a plurality of first optical signal portions and a plurality of second optical signal portions; a first plurality of optical delay interferometer circuits, each of which being configured to receive the plurality of first optical signals portions and supply a corresponding one of a plurality of delayed first optical signal portions, each of the plurality of delayed first optical signal portions being delayed relative to a corresponding one of the plurality of second optical signal portions; a second plurality of optical power splitters, each of which being configured to receive a corresponding one of the plurality of second optical signals output from the second optical demultiplexer, and output a plurality of third optical signal portions and a plurality of fourth optical signal portions; and a second plurality of optical delay interferometer circuits, each of which being configured to receive the plurality of third optical signals portions and supply a corresponding one of a plurality of delayed third optical signal portions, each of the plurality of delayed third optical signal portions being delayed relative to a corresponding one of the plurality of fourth optical signal portions.