Performance degradations of 2.4 Gbit/s NRZ/RZ lightwave systems due to reflection-induced phase-to-intensity-noise conversion

Performance degradations in 2.4-Gb/s NRZ (nonreturn to zero) and RZ lightwave systems due to phase-to-intensity-noise conversion between two connectors have been evaluated using computer simulation techniques. Both NRZ and RZ systems have approximately the same penalty if the roundtrip time delay between the two connectors is an exact integer number of bits. If the roundtrip time delay is slightly offset, however, the RZ system penalty is significantly reduced. For example, the RZ system penalty is reduced from 3 dB (roundtrip delay between the two connectors=40 b) to 1.5 dB (roundtrip delay=40.5 b) for two connectors with 8-dB return loss each.<>