Longitudinal-mode behavior of lambda /4-shifted InGaAsP/InP DFB lasers fabricated by the nega-posi method have been studied. The deviation of the main mode from the center of the stopband, which was attributed to an accidental additional phase shift introduced around the lambda /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.
|Number of pages||3|
|Publication status||Published - 1985 Jan 1|
ASJC Scopus subject areas
- Electrical and Electronic Engineering