High speed driving of gain-switched LD with exponential transmission line

With the increasing information capacity of airborne system, there is an increasing need for high speed drives for laser diode (LD). In order to match the low resistive LD, an exponential transmission line is proposed which is used for compensation of the pattern effect in gain switching of laser diodes as well as to overcome the effect of parasitic elements in high-speed drives to improve the rise and trail edges of the output waveform. An accurate circuit model of the exponential line for PSPICE program is developed and simulations are carried out by employing the PSPICE program.