Longitudinal-Mode Behaviour Of λ/4-Shifted InGaAsP/InP DFB Lasers

K. Utaka, S. Akiba, K. Sakai, Y. Matsushima

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Longitudinal-mode behaviour of λ/4-shifted InGaAsP/lnP DFB lasers fabricated by the nega-posi method have been studied. The deviation of the main mode from the centre of the stopband, which was attributed to an accidental additional phase shift introduced around the λ/4-shifted position, was related to the intensity ratio of the main to side mode below the threshold, and it was much larger compared to conventional DFB lasers for the devices with small deviation. The intensity ratio above the threshold was about 35 dB or more in 100% direct modulation for most of the lasers.

Original languageEnglish
Pages (from-to)367-369
Number of pages3
JournalElectronics Letters
Issue number9
Publication statusPublished - 1985 Jan 1
Externally publishedYes


  • Lasers and laser applications
  • Semiconductor lasers

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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