Heat Effects on Data Transmission by Laser Diode and Light Emitted Diode for High Frequency Optical Communication Systems

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 – 250 MHz) with tunable pulse width, Different laser diodes with (650 nm) and LED with 650 nm wavelength had be used, 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 °C) was also employed. All optical sources had be operated with different frequencies (50 kHz – 250 MHz) and different triggers (10% - 90%) of pulse duration, with high operation frequencies. 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. For a laser diode (635 nm) the spectrum shift was (3.21 nm to 4.9 nm). The Light emitter diode (LED) was very stable during the different operating conditions and the change in temperature and operating frequency. The spectrum shift was zero with no change in temperature.