Patent ID: 7346283
Filing Date: 2008-03-18
Classification: H04B

Abstract:
1. An apparatus for generating a chirped return-to-zero (CRZ) differential quadrature-phase-shift-keyed (DQPSK) optical signal comprising: means for generating a first return-to-zero (RZ) drive signal and a second RZ drive signal using a first tributary of a data signal; modulator means driven by the first and second RZ drive signals for providing simultaneous RZ pulse formatting and chirped DPSK data modulation to an optical signal to generate a CRZ-DPSK optical signal; means for generating a non-return-to-zero (NRZ) drive signal based on a second tributary of the data signal; modulator means driven by the NRZ drive signal for receiving the CRZ-DPSK optical signal and phase shifting the CRZ-DPSK signal by 0 or π/2 to generate the CRZ-DQPSK optical signal.