Theory of cutoff temperature of operation of uncooled semiconductor laser diode

Computer & Network Security Research Group, Faculty of Engineering & Built Environment, Department of Electrical, Electronic and Systems Engineering, University kebangsaan Malaysia (UKM) (National University of Malaysia), 43600 Bangi, Selangor, Malaysia

Corresponding author: mrhassan75@yahoo.com

Received: 15 January 2010
Accepted: 3 February 2010
Published online: 26 March 2010

Abstract

In this paper, the authors present a new theory that can be applied to predetermine the value of cutoff temperature of operation (T_cutoff) of uncooled semiconductor laser diodes. T_cutoff is defined as the value of temperature of operation above which, the turn-on time delay t_on of uncooled SLD will exceed the bit time interval of the injected pulse and results in an inoperable case. An analytical model is derived to represent the temperature dependence of t_on. This model is used to derive an accurate one for T_cutoff and in terms of laser cavity parameters. Simulation results show that T_cutoff can be increased (improved) by increasing the injection current or biasing the uncooled SLD near threshold. The benefit of this study is that the designer could predetermine previously the requirements that should be taken into account, when considering of uncooled SLD in high-speed optical communication systems.