Abstract

Frequency-stabilized optical sources are necessary for optical FDM systems.^1,2 For these sources the application of commercially available laser-diode (LD) modules with a Peltier cooler and a thermistor has been investigated.³ The frequency of this type of LD module is stabilized by controlling LD injection current and temperature without external frequency references. In this case the LD temperature is measured indirectly by a thermistor bonded beside the LD. However, a thermal resistance between the LD and the thermistor causes a temperature difference between these two positions, and this temperature difference varies with package temperature. Therefore the frequency of the LD drifts according to the package temperature, although the Peltier cooler is controlled so as to keep the thermistor temperature constant.

© 1993 Optical Society of America