Laser diode beam shaping with GRIN lenses using the twisted beam approach and its application in pumping of a solid-state laser

We report a novel beam shaping method for laser diodes based on the concept of twisted Gaussian Schell-model beams using GRIN lenses. This method enables a more symmetric pump as well as a compact setup for pumping of solid-state lasers. In the experiment with a standard 2 W diode, the beam quality factors in the two orthogonal directions were equalized to Mx2≈24 and My2≈18, respectively, which pumped an intra-cavity frequency-doubled Nd:YAG laser at 946 nm with an output of 28 mW at 473 nm.