IF FILTER BANDWIDTH OPTIMIZATION OF COHERENT HETERODYNE ANALOG FM OPTICAL RECEIVER

The performance of the coherent heterodyne optical FM receiver employi ng a discriminator has been simulated under different i.f. filter band -widths to find the optimal bandwidth. The value of the signal-to-nois e ratio has been obtained under different values of i.f. filter bandwi dth, modulation index, and signal power. The phase noise linewidth is fixed at Delta nu = 10 kHz. Even for very small linewidths the perform ance of the coherent optical FM receiver is mainly dominated by phase noise. The advantage of FM modulation exists only when received signal power is small. (C) 1995 John Wiley and Sons, Inc.