Abstract

The boost on gain, differential gain and reduction of the linewidth enhancement factor in InGaAs on InP system due to compressive strain have recently been demonstrated theoretically[1-3]. The linewidth enhancement factor a (hereafter termed as the a parameter) is a key parameter in determining wavelength chirping and laser linewidth. Up to now, theoretical studies on strained quantum well(QW) lasers have been limited to lasing characteristics at gain peak, which implies the assumption of Fabri-Perot cavity. On the other hand, distributed feedback(DFB) lasers, which is an indispensable light source in optical transmission system, have the feature where the lasing wavelength can be tuned independent of the gain peak. The application of this feature is called detuning. In this paper, we discuss ways of designing lasers with extremely small a parameter(chirpless lasers) by detuning strained modulation doped(MD) QW lasers.

© 1992 Optical Society of America