A novel digital degenerate cavity laser (DDCL) arrangement [1,2], with which it is possible to digitally control the intensity, phase and coherence of about 100,000 pixels in a two dimensional laser distribution is presented. It is comprised of a reflective phase-only SLM at one end, a gain medium, an output coupler at the other end, an intra-cavity 4f telescope, and an intra-cavity aperture. The combination of the SLM and the intra-cavity aperture serves as a mirror with variable reflectivities and phases[3]. In addition, the intra-cavity aperture controls the coherence of the laser beam. The variations of reflectivities, phases and coherence can be exploited in various applications, including generation of high order Hermite Gaussian beams, development of shaped beams that are propagation invariant over relatively long distance and rapidly solving optimization problems such as phase retrieval problems. The details of the laser arrangement, procedure, and experimental results of the various applications will be presented.

References:

1. M. Nixon, E. Ronen, A. A. Friesem, and N. Davidson, "Observing Geometric Frustration with Thousands of Coupled Lasers," Phys. Rev. Lett. 110, 184102 (2013).

2. R. Chriki, M. Nixon, V. Pal, C. Tradonsky, G. Barach, A. A. Friesem, and N. Davidson, "Manipulating the spatial coherence of a laser source," Opt. Express 23, 12989 (2015).

3. S. Ngcobo, I. Litvin, L. Burger, and A. Forbes, "A digital laser for on-demand laser modes," Nat. Commun. 4, 1–6 (2013).