High optical-to-optical efficiency of LD pumped cw Nd:YAG laser under pumping distribution control

00 operation have been investigated under different pump light distributions that have been formed by a virtual-point-source pumping system. Compared with a central uniform distribution, a centrally depressed distribution is found to have a lower thermal lensing effect and a higher optical-to-optical efficiency for operations performed using the same resonator parameters or within a similar stable range, and the improvement in optical-to-optical efficiency is explained as a result of a reduction in thermally induced aberrations.