W. Muys

Simultaneous suppression of stimulated Brillouin scattering and interferometric noise in externally modulated lightwave AM-SCM systems

Externally modulated AM-SCM lightwave systems employing optical power amplifiers, small linewidth DFB lasers and long optical feeder lines, face low stimulated Brillouin scattering threshold powers and phase-to-intensity noise conversion by multipath interference through Rayleigh scattering. We show that these problems can be effectively counteracted simultaneously without introducing additional intermodulation distortion, both by single tone phase modulation and by dithering of the lasers optical frequency.<<ETX>>

A 50-channel externally modulated AM-VSB video distribution system with three cascaded EDFA's providing 50-dB power budget over 30 km of standard single-mode fiber

Presents an externally modulated 50-channel AM-VSB video lightwave system, employing three cascaded EDFAs. For system specifications of SNR=46 dB, CSO<-66 dBc and CTB<-55 dBc, up to 40 000 ONUs can be connected to a single transmitter unit at distances larger than 30 km with standard nondispersion-shifted fiber. Interferometric noise and SBS are suppressed using single-tone phase modulation.<<ETX>>

Mutual deterioration of WDM-coupled AM-CATV and digital B-ISDN services in single fiber access networks

In single-fiber access networks with interactive and distributive services multiplexed at different wavelengths, the interactive signal may disturb the distributive signal, and vice versa, because of imperfect isolation of the demultiplexing WDM at the subscriber site. The mutual deterioration of a 622-Mb/s intensity-modulated (IM) broadband ISDN (B-ISDN) signal at 1.3 mu m and an AM subcarrier-multiplexed (SCM) TV-distribution signal at 1.55 mu m is investigated. Both theory and experiment show that the isolation of the demultiplexing WDM must keep the undesirable 1.3- mu m, 622-Mb/s IM signal power on the analog receiver below -36 dBm to avoid degradation of the analog system CNR of 47 dB by more than 1 dB.<<ETX>>

Experimental verification of self-phase-modulation-induced nonlinear distortion in externally modulated AM-VSB lightwave systems

Self-phase-modulation (SPM) in intensity-modulated systems causes frequency chirp, which in combination with fiber dispersion generates second-order distortion. It has been shown theoretically that in externally modulated systems, this effect can cause intolerable amounts of composite second-order (CSO) distortion, if the length of the feeder section between the CATV head-end and the local exchange exceeds a few tens of kilometers. We will for the first time present experimental data, supporting the theoretical analysis.

Numerical simulation of clipping induced distortion in externally modulated lightwave AM-SCM systems

For the first time to our knowledge the results of numerical simulation, and experimental verification, of clipping induced distortion in externally modulated lightwave AM-SCM CATV systems are presented. Comparison of these results with clipping induced distortion in directly modulated systems show a remarkable outcome: under the same modulation conditions the composite triple beat (CTB) distortion component in externally modulated systems is 6 dB higher than in directly modulated systems.<<ETX>>

Directly modulated AM-VSB lightwave video transmission system using dispersion-compensating fiber and three cascaded EDFAs, providing 50-dB power budget over 38 km of standard single-mode fiber

Summary form only given. In this paper we show that with a directly modulated transmitter in a CATV transport and distribution system with cascaded Er-doped fiber amplifiers (EDFAs) similar power budgets and transmission distances can be achieved as in an externally modulated system, without electronic predistortion, by using dispersion compensating fiber (DCF) and carefully designed EDFAs with low gain-slope.