Characteristics comparsion pf backward and forward pumped spectrum pre-sliced multi-wavelength fibre sources

摘要

A double pass Mach-Zehnder interferometer (DPMZI) is analysed by taking the polarization effects into account and then optimized to exhibit a high extinction ratio (ER), larger than 41 dB, to weaken its limitation on the ER of the spectrum pre-sliced multi-wavelength fibre source (SP-MWFS). With the optimized DPMZI as the comb filter, the backward and the forward pumped SP-MWFSs have been compared in aspects of ER, channel bandwidth and output power. The latter provides a higher ER yet with a lower output power than the former. The ER and channel bandwidth of both configurations changes with pump power, yet in different ways. A discussion about these phenomena is given. A bi-direction pumping configuration is suggested in order to obtain high ER and large output power simultaneously.