Abstract

Analog subcarrier-multiplexed lightwave systems that carry 40- 80 AM-virtual-sideband (AM-VSB) channels have become established for transmission of the cable-television signal.¹ Increasingly, applications that include a mix of channel types, AM-VSB and digital or quadrature amplitude modulation (QAM), are being considered. A large amount of polarizationmode dispersion (PMD) in the lightwave path has been seen to adversely affect the performance of AM-VSB systems by generating second-order distortion.^2,3 Will a QAM channel transmitted over a lightwave link with large PMD also be degraded? We measured the performance of a 64-QAM channel as a function of the second-order distortion introduced by PMD in the lightwave transmission path. The degradation in the bit error rate (BER) was compared to that caused by noise and by distortion from other sources.

© 1994 Optical Society of America