Characterisation of a Q-switched TEM00 Nd:YAG laser for processing single and polycrystalline diamonds

in the present investigation, a Q-switched Nd:YAG laser is characterized and used to study the various aspects of single and polycrystalline diamond processing. The experimental setup mainly consists of a Q-Switched Nd: YAG laser at 1064nm with a maximum average power of 18 W at 4 KHz. Inorder to check the accuracy of the focused laser beam and to find out an exact diamond cutting operating power and frequency range, the variation of beam diameter at the. output coupler and thermal lens focal length at different Nd doping concentration of active medium and energy density at the work piece are found out. The diamond cutting is performed by making the "V" shaped groove with various opening angle. The variation of weight loss of diamond during cutting and time taken for the process are noted. The Q-Switched Nd:YAG laser system is showing very good performance in terms of peak to peak out put stability, minimal spot diameter, smaller divergence angle, higher peak power in Q-Switched mode and good fundamental TEM00 mode quality for processing natural diamond stones. Minimum weight loss, less micro-cracks and good surface quality of diamonds are achieved.