Title :
Effects of laser direct intensity modulation index on optical beat interference in subcarrier multiplexed wavelength division multiple access networks
Author :
Banat, M.M. ; Kavehrad, M.
Author_Institution :
Dept. of Electr. Eng., Ottawa Univ., Ont., Canada
Abstract :
Degradation in carrier-to-interference ratio (CIR) due to optical beat interference (OBI) in subcarrier multiplexed wavelength division multiple Access (SCM/WDMA) networks using direct photodetection is evaluated. The subcarriers are assumed to directly intensity modulate separate lasers. A large signal model for the modulated laser light is used. The discrepancy in CIR between this model and the small signal model commonly used in the literature is important at high modulation indices (4.5 dB at about unity modulation index). This justifies the introduction of the large signal model for analyzing OBI. It is found from analytical results that OBI is lower for higher intensity modulation indices.<>
Keywords :
multi-access systems; optical fibre communication; optical fibre networks; optical fibres; optical modulation; optical signal detection; photodetectors; subcarrier multiplexing; CIR; SCM/WDMA; carrier-to-interference ratio; data transmission; direct photodetection; large signal model; laser direct intensity modulation; modulated laser light; modulation index; optical beat interference; optical fibre; small signal model; subcarrier multiplexing; wavelength division multiple access networks; Degradation; Intensity modulation; Interference; Laser modes; Optical fiber networks; Optical modulation; Optical network units; Signal analysis;
Journal_Title :
Communications, IEEE Transactions on
