Adaptable beam profiles from a dual-cavity Nd:YAG laser

We report a technique to tailor a laser beam profile from a donut to quasi-top-hat intensity distribution, directly from the laser, simply achieved by simultaneous excitation and control of the relative contributions of the fundamental (TEM00) and first-order Laguerre-Gaussian (LG(01)) transverse modes. Exploiting a dual-cavity configuration with a single Nd: YAG gain element, adaptable continuous-wave laser beam profiles from the primary cavity could be obtained by varying the diffraction loss of an acousto-optic modulator in the secondary cavity. We investigate the resultant beam profiles as a function of pump power and the AOM diffraction loss, and discuss the prospects for tunable laser beams profiles. (C) 2016 Optical Society of AmericaNational Research Foundation (NRF) (NRF-2014R1A1A2A16053885)