Structured Light Laser Based on Intra-Cavity Modulation

Structured light fields carrying orbital angular momentum (OAM) have been widely studied, and a variety of applications have been found. The exploration of the generation of the structured light beams with higher purity, order, and efficiency has become an inevitable trend. In early years, structured light beams are normally generated with the extra-cavity methods, as it is simpler in principle. However, the intra-cavity generation of the structured light has a better beam purity and higher light conversion efficiency. Here, the current advance in the production of structured light directly from lasers based on spatial light modulators (SLMs), metasurfaces, and microrings is reviewed.