Figure 4 : Customized spatial modes by amplitude and phase modulation.

From: A digital laser for on-demand laser modes

Figure 4

By complex amplitude modulation, a customized set of high-loss regions create a Hermite–Gaussian beam (n=3, m=0) and a superposition of Laguerre–Gaussian beams (p=0, l=±4) as the laser output. By phase-only modulation, a flat-top beam and Airy beam are created as the stable modes of the cavity. Combining amplitude and phase effects allows for the selection of a Laguerre–Gaussian beam (p=1, l=0) of a chosen size.