Demonstration of a novel optical transmitter for high-speed differential phase-shift-keying/inverse-return-to-zero (DPSK/inv-RZ) orthogonally modulated signals

We propose and experimentally demonstrate a simple and novel optical transmitter for superimposing 10-Gb/s differential phase-shift-keying signals on a 10-Gb/s inverse-return-to-zero signal. The proposed transmitter comprises a dual-drive Mach-Zehnder intensity modulator and an optical phase modulator. Its performance has been experimentally characterized.