Heat Effects on Spectrum Shift by Laser Diode (780 and 808 nm) in High Frequency for Optical Communication Systems

Abstract

Laser Diode are vastly used in fields of free space optical and fiber optical communication systems, which become needful devices in the systems and equipment making up the infrastructure of our society. In this paper a laser diode power supply with controller oscillator had be designed and operated with different frequencies (50 kHz – 2 MHz) with tunable pulse width, Different laser diodes with (780nm and 808 nm), An optical spectrum analyzer with spectrum range (200 – 1050 nm) had been used to test the output spectrum, A digital thermometer to measure  the temperature and thermo electric cooler (TEC) to controller the device temperature (20 – 50 Co) was also employed. All optical sources had be operated with different frequencies (50 kHz – 2 MHz). The device temperature had increased proportionally and the trigger width was the main factor. The best spectrum stability was at a trigger (10%) of pulse duration. With temperature increase, the output spectrums showed Red-shift and expansion in spectrum width, via temperature controller with TEC and metallic heat sink. The instability was controlled in output spectrum the for a laser diode (780 nm) the spectrum shift was (1.18 nm to 2.94 nm). While, for a laser diode (808 nm) the spectrum shift was (6.12 nm to 9.19 nm).