Next Generation 10 Gb/s RZ Optical Transmitters

Abstract

We propose an alternate chirp RZ optical transmitter that provides telecommunication carriers with a cost effective solution for upgrading the existing 2.5 Gb/s fiber links to 10 Gb/s. The performance of the proposed alternate chirp RZ transmitter has been compared with the chirp-free RZ with 33% duty cycle, chirp-free RZ with 50% duty cycle, and NRZ transmitters. Two dispersion compensation schemes have been used in the evaluation. In the first scheme, the fiber dispersion is compensated at the transmitter and receiver sites (end-to-end compensation) for 1000 km and 2000 km links. In the second scheme, the fiber dispersion is compensated every 640 km where optical switches are normally located. Computer simulation results indicate that RZ transmitters are better than NRZ transmitter for both dispersion compensation schemes. They also indicate that alternate chirp RZ transmitter can tolerate nonlinear effects than other classical chirp-free RZ transmitters for transmission up to 2000 km using end-to-end compensation scheme. Transmission up to 4000 km using dispersion compensation every 640 km is also possible using alternate chirp RZ transmitter but not possible with chirp-free RZ transmitters nor NRZ transmitter.