Crosstalk degradation caused by optical amplification in a multichannel FSK heterodyne system
- 1 May 1989
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in Journal of Lightwave Technology
- Vol. 7 (5) , 759-765
- https://doi.org/10.1109/50.19111
Abstract
The crosstalk degradation caused by an optical amplifier in a four-channel FSK (frequency-shift-keyed) heterodyne communication system is measured. A bit error rate (BER) floor of 3*10/sup -4/ is observed when the channels are spaced by 200 MHz, FSK modulation at 45 Mb/s, and when the optical input signal is large enough such that the gain is compressed by 2 dB relative to its small-signal value. The receiver is substantially improved by reducing the optical power amplifier input. However, the sensitivity increases only to a maximum value beyond which it degrades as the optical power of the demodulated channel becomes small relative to the noise of the optical amplifier. The combined effect of the crosstalk and the amplifier noise yields an optimum sensitivity of 250 photons/b for BER=10/sup -9/. This result is 5 dB poorer than the sensitivity obtained in the absence of an optical amplifier.Keywords
This publication has 23 references indexed in Scilit:
- Nonlinear interactions in optical amplifiers for multifrequency lightwave systemsElectronics Letters, 1988
- Measurement of carrier-density mediated intermodulation distortion in an optical amplifierElectronics Letters, 1987
- Intermodulation distortion in optical amplifiers from carrier-density modulationElectronics Letters, 1987
- Crosstalk penalty in a two-channel ASK heterodyne detection system with non-negligible laser line widthElectronics Letters, 1987
- Amplifier-induced crosstalk in multichannel coherent lightwave systemsElectronics Letters, 1987
- Nearly degenerate four-wave mixing in a traveling-wave semiconductor laser amplifierApplied Physics Letters, 1987
- Densely spaced WDM coherent optical star networkElectronics Letters, 1987
- Four-wave mixing and phase conjugation in semiconductor laser mediaOptics Letters, 1987
- Fast frequency-tunable external-cavity laserElectronics Letters, 1987
- Collinear nearly degenerate four-wave mixing in intracavity amplifying mediaIEEE Journal of Quantum Electronics, 1986