Distributed feedback InGaAsP lasers.
01 January 1986
The operating characteristics of distributed feedback (DFB) InGaAsP lasers are reviewed from the point of view of their applications in optical communication systems. The wavelengths and the threshold gains of the allowed longitudinal modes of a DFB laser are obtained using the coupled-wave theory after incorporating both the facet reflections and the grating-induced distributed feedback. The experimental results are presented for 1.55micron DFB semiconductor lasers. In particular, we discuss the temperature dependence of the threshold current and the emission wavelength, the modulation response, the frequency chirp, and the linewidth of the single longitudinal mode selected by the DFB mechanism.