In this paper we report original results related to the degradation of laser diodes parameters, as they are subjected to electron-beam and gamma-ray irradiation. For this purpose, we investigated two double heterostructures laser diodes, operating at 808 nm, 850 nm respectively. The maximum emitted optical power was in the range of 5 -6 mW, in CW operation mode. Radiation induced modifications of laser diodes electrical, optoelectrinc and optical parameters were studied. Simultaneously, the responsivity of the embedded photodiode was monitored. Slightly changes in the laser threshold current, emitted radiation wavelength, serial resistance and external quantum efficiency were observed, while more important variations of the photodiode responsivity and laser diode spectral distribution were noticed. The temperature dependence of device parameters after the irradiation was also studied. The work under way is performed in the frame of EU’s Fusion Programme.
Several low power medical laser devices were studied. We focused on power, wavelength and beam characteristics (2D and 3D images, point stability, beam profile, gaussian fit and elliptical axis etc). The variation of laser parameters for different time intervals and room temperatures was studied.