Title :
Suppression of RF noise tones caused by Rayleigh backscatter in to an unisolated laser using audio-frequency external optical-phase modulation
Author :
Gan, Hongbing ; Lowery, Arthur J. ; Lauder, Richard D T
Author_Institution :
Dept. of Electr. & Electron. Eng., Melbourne Univ., Parkville, Vic., Australia
Abstract :
When Fabry-Perot lasers are subject to Rayleigh backscatter, dramatic line-narrowing and frequency hopping up to 500 MHz, evidenced by radio-frequency (RF) tones, are observed. These RF tones will severely degrade the system performance of a subcarrier multiplexed transmission system, such as quadrature phase-shift keying. In this letter, it is demonstrated that audio-frequency external optical-phase modulation can suppress the noise tones and restore the laser linewidth. This scheme may offer an inexpensive alternative to optical isolators to recover the system performance and thus is very important for cost-effective customer access networks.
Keywords :
Rayleigh scattering; backscatter; laser noise; optical fibre subscriber loops; optical isolators; optical modulation; quadrature phase shift keying; RF noise tone suppression; RF tones; Rayleigh backscatter; audio-frequency external optical-phase modulation; cost-effective customer access networks; dramatic line-narrowing; frequency hopping; laser linewidth; optical isolators; quadrature phase-shift keying; subcarrier multiplexed transmission system; system performance; unisolated laser; Backscatter; Degradation; Fabry-Perot; Laser noise; Optical fiber networks; Optical modulation; Optical noise; Phase shift keying; Radio frequency; System performance;
Journal_Title :
Photonics Technology Letters, IEEE
