Title :
Multiple optical reflections in hybrid AM/16-QAM multichannel video lightwave transmission systems
Author :
Ovadia, Shlomo ; Eskildsen, Lars ; Lin, Chinlon ; Anderson, William T.
Author_Institution :
Bellcore, Red Bank, NJ, USA
Abstract :
The effects of multiple optical reflections on bit-error-rate characteristics using a directly-modulated DFB laser transmitter and an externally-modulated YAG laser transmitter are compared in hybrid multichannel AM/16-QAM video lightwave transmission systems. The measured 16-QAM bit-error-rate is increased from 10/sup -10/ at reflections of -60 dB to 10/sup -1/ at reflections of -20 dB for a 16-QAM modulation index of 0.22% using the DFB laser transmitter (AM modulation index of 3.3%) with an analog CNR of 52 dB. In contrast, the observed 16-QAM bit-error-rate is essentially unaffected by reflections using an externally-modulated YAG laser transmitter with the same AM modulation index and received optical power.<>
Keywords :
amplitude modulation; light reflection; optical links; optical modulation; video signals; visual communication; AM modulation index; YAG; YAl5O12; analog CNR; bit-error-rate; directly-modulated DFB laser transmitter; externally-modulated YAG laser transmitter; hybrid AM/16-QAM multichannel video lightwave transmission systems; multiple optical reflections; optical power; Acoustic reflection; Fiber lasers; Laser noise; Optical interferometry; Optical noise; Optical reflection; Optical transmitters; Power lasers; Quadrature amplitude modulation; Video compression;
Journal_Title :
Photonics Technology Letters, IEEE
