Fig. 3: Observation of Boyer-Wolf Gaussian modes.

a Experimental setup of the 2:1 anisotropic resonator cavity that lases in Boyer-Wolf Gaussian modes. The laser cavity of length \(L\) is composed of a Nd:YAG flat crystal that acts as an output coupler and gain medium, a vertical cylindrical lens of focal length \(f\), in the middle of the cavity, and a horizontal cylindrical mirror with \(R=2(2f).\) The cavity is pumped by focusing a \(808{nm}\) light from a laser diode into the Nd:YAG crystal. b Measured laser beam intensity patterns of the first eighteen Boyer-Wolf Gaussian modes with \(l \, > \, 0\), at the output coupler of the resonator. The mode order and degree \((n,l)\) are displayed in the bottom right corner of each panel. The scale of the modes is normalized to their width \({w}_{0}\) (inset of the bottom-right panel). The specific resonator length and width for each mode are provided in the Supplementary Information.