Encoding and Transmission of Orthogonally Optical Label Switching Using DQPSK Payloadand MD-RZ Label

Optical label switching (OLS) has beenregarded as an effcient technique to route and forwardIP packets transparently in the optical layer. In labelswitching system, Modified duobinary Return zero (MDRZ) label and Differential quadrature phase-shift-keying(DQPSK) payload have not been used yet. We proposea novel optical label switching scheme by the combination MD-RZ label and DQPSK payload for the first time.The transmitter is set up by cascading two Phase modulators (PMs) and one dual-arm LiNbO₃ modulator. Dutycycle and extinction ratio of the MD-RZ labels are tunable. The DQPSK payload can be used in a 20Gbit/s optical label switching system, with 2-bit per symbol modulation/demodulation. The transmission performance of2.5Gbit/s MD-RZ label is also analysed. MD-RZ labelingof a DQPSK payload has been shown to be a promisingcandidate for the implementation of OLS system.