Patent ID: 7277646

Claim:
An optical transmitter for generating an optical signal, comprising: a precoder configured to code an electrical signal of binary data; a continuous-wave (CW) light source configured to generate a continuous wave light; an optical phase modulator configured to modulate the phase of an optical signal outputted from the CW light source according to an electrical signal outputted from the precoder; a birefringent material configured to apply a time delay to a signal outputted from the optical phase modulator, depending upon the polarization state inputted to the birefringent material; and a polarizer configured to permit only optical signals having a specific polarization direction to transmit therethrough when optical signals outputted from the birefringent material are applied, wherein the polarizer comprises a polarization beam splitter that is configured to produce a duobinary signal as one output and an alternate mark inversion (AMI) signal as another output.