Frequency stabilization of semiconductor lasers for applications in coherent communication systems

A. Sollberger, Arja Heinämäki, M. Melchior

Research output: Contribution to journalArticleScientific

17 Citations (Scopus)


The stabilization of the mean frequency of a single-mode semiconductor laser used under modulation in a FSK heterodyne transmission system is achieved by a novel method. The frequency stabilization scheme locks the laser to one of the resonance frequencies of a Fabry-Perot interferometer (FPI).
The laser is weakly modulated at a frequency higher than any signal frequencies. Light reflected from the FPI is detected and synchronously demodulated for feedback and current control of the laser. A laser modulated by a pseudorandom sequence with a rate of 140 Mbit/s and an optical frequency deviation of 280 MHz is stabilized with this method against variations in operating temperature and bias current.
The mean optical frequency is maintained within ± 10 MHz for hours. Analysis and experiments confirm that the laser frequency remains stable even when the laser linewidth changes under weak optical feedback.
Original languageEnglish
Pages (from-to)485-491
JournalJournal of Lightwave Technology
Issue number4
Publication statusPublished - 1987
MoE publication typeB1 Article in a scientific magazine


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