Design of a stabilized, dc-powered analog laser diode driver

Abstract

This thesis presents the design, implementation and evaluation of a depowered, stabilized-output laser diode drive unit for use in an analog fiber- optic communication transmitter. The driver circuits provide for a stable temperature-controlled operating environment by monitoring the thermistor in the laser diode module and by controlling the current to the module's integral thermoelectric cooler. Output optical power is maintained at desired bias and peak-to-peak levels by processing the signal from the monitor photodiode and amplifying (if necessary) the ac and dc drive units. These efforts offset the degradation of the laser diode's capabilities due to heat and age.