Effect of Nd3+ concentration on CW and pulsed performance of ???ber-coupled diode laser pumped Nd:YVO4 laser at 1064 nm

摘要

The effect of Nd3+ concentration on the CW and Q-switched laser performances at 1064 nm from Nd : YVO4 has been studied under diode laser pumping in identical laser con???guration. The Nd3+ concentrations used were 1, 2 and 3 at. % in YVO4 crystals. Under the CW operations we have compared the thermal lensing effect, slope ef???ciencies and also the beam quality at the fourth-order degeneracy con???guration. Q-switching was done with the help of an acousto-optic modulator and we have compared the pulses obtained from Nd : YVO4 laser with different doping concentration. It was found that the 1 at.%-doped crystal is the best, offering highest optical-to-optical conversion ef???ciency (55%), lowest fractional heat load (24%), highest pulse energy (80 e???J) and shortest pulse width (20 ns). It was also found that there was not much difference in performances for 2 and 3 at. %-doped crystals both in CW and Q-switched con???gurations.