Patent ID: 8233510

Claim:
An optical circuit comprising: a semiconductor substrate; and a laser provided on the semiconductor substrate, the laser having first and second outputs, the first output supplying first light and the second output supplying second light; a first modulator being configured to modulate the first light to thereby supply a first modulated optical signal carrying first data stream; a second modulator being configured to modulate the second light to thereby supply a second modulated optical signal carrying a second data stream; a polarization rotator configured to rotate a polarization of the first modulated optical signal, such that the first modulated optical signal has a first polarization and the second modulated optical signal has a second polarization that is different than the first polarization; and a polarization beam combiner having an output, the polarization beam combiner being configured to receive the first and second modulated optical signals and combine the first and second modulated optical signals at the output of the polarization beam combiner.