Symmetric operating point for increasing the extinction ratio of semiconductor based optical loop mirrors

Nigel Johnson, James A. Harrison, Keith Blow

Research output: Contribution to journalArticle


Terahertz optical asymmetric demultiplexors (TOADs) use a semiconductor optical amplifier in an interferometer to create an all-optical switch and have potential uses in many optical networking applications. Here we demonstrate and compare experimentally a novel and simple method of dramatically increasing the extinction ratio of the device using a symmetrical configuration as compared to a ‘traditional’ configuration. The new configuration is designed to suppress the occurrence of self-switching in the device thus allowing signal pulses to be used at higher power levels. Using the proposed configuration an increase in extinction ratio of 10 dB has been measured on the transmitted port whilst benefiting from an improved input signal power handling capability.
Original languageEnglish
Pages (from-to)2777-2783
Number of pages7
JournalJournal of Modern Optics
Issue number17
Publication statusPublished - 1 Oct 2008



  • optical processing
  • SOAs
  • wavelength conversion

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