Suppression of RF noise tones caused by Rayleigh backscatter in to an unisolated laser using audio-frequency external optical-phase modulation

Hongbing Gan, Arthur J. Lowery, Richard D.T. Lauder

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)


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.

Original languageEnglish
Pages (from-to)1778-1780
Number of pages3
JournalIEEE Photonics Technology Letters
Issue number12
Publication statusPublished - 1 Dec 1998
Externally publishedYes


  • Audio frequency
  • Customer access network
  • Noise suppression
  • Optical-phase modulation
  • Rayleigh backscatter

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