Authors: M.A. Iqbal, S. Ghani
Affilation: PUNJAB UNIVERSITY, Pakistan
Pages: 69 - 72
Keywords: AlGaInP based laser, photodiode, gamma, ray radiation, threshold current
Analysis of effect of temperature in the range (280k-300k) and radiation (X-rays and γ rays) on the AlGaInP based laser at 665nm emission wavelength has been carried out. Before and after irradiation, current-voltage (I-V), light-current (L-I), and photodiode monitor current vs. light (Im-L) characteristics have been studied at different fixed temperatures. I-V curve varies little over radiation and temperature. Threshold voltage needed for lasing varies linearly with temperature. Threshold current increases exponentially with temperature. Output power decreases in non-linear manner with temperature. It is due to non-radiative recombination at higher temperature. Diodes were exposed to γ ray source for different doses. Significant changes occur in output power and photodiode response. Such laser diodes based on QW structure proved to be immune to radiation, as its size is very small. The monitor photodiode is adversely affected by irradiation process, as they are simple junctions. Degradation of LD occurs at high doses of radiation.