الفهرس | Only 14 pages are availabe for public view |
Abstract A pulsed home-made Nd:YAG laser system has been designed and constructed which can be used as a laser source in laser induced breakdown spectral measurements (LIBS).The wavelength of Nd:YAG laser system is 1064 nm. The steps of construction of the system can be listed as follow: A single elliptical pump reflector cavity has been designed with CNC machine where (2a = 3.4 cm), (2b = 2.75 cm) and (2c = 1.999 cm). The cavity has been coated with gold to increase the efficiency. The optical pumping efficiency of the designed cavity is about 65%. Xenon flash lamp has been used as an optical pumping source. To fire the lamp, a driver circuit has been designed. Different mirror reflectivities have been used 40, 50 and 60%. The output laser energy increased with increasing the output coupler reflectivity. Accordingly, the maximum output laser energy is 836.6 mJ with a pulse duration 360 μs and a pulse repetition rate of about 1 Hz. To ensure the performance of the constructed system, the laser output has been used as an ablation source of cadmium oxide thin film and the spectral emission has been investigated in the range from 100-1100 nm. The main peaks has been identified and marked based on the NIST (National Institute of Standards and Technology). The observed spectral lines of cadmium are 588.022, 675.919 and 734.56704 nm. |