On-demand spatial modes and vortex beams from a visible Pr:YLF orbital Poincaré laser with a hybrid pumping scheme

The controlled visible spatial modes and vortex beams with tunable properties are highly sought after in cutting-edge applications, such as optical communication. In this study, by utilizing a hybrid pumping scheme, we demonstrate an ultra-compact, 607 nm orbital Poincaré laser based on a diode-pumped Pr:YLF laser. The system can generate various structured modes, including Laguerre-Gaussian (LG), Hermite-Gaussian (HG), and Hermite-Laguerre-Gaussian (HLG), all of which are mapped onto a first-order orbital Poincaré sphere. A numerical analysis of the coherent superposition of HG modes with varying phases is in complete agreement with the experimental results. The handedness of the generated vortex beam can be selectively controlled by precisely adjusting the angle of output coupler. In comparison to other schemes, the hybrid pumping scheme offers advantages of high precision and excellent tunability, enabling the emitting of high-order HG modes, LG modes, along with a wide range of spatial modes on the orbital Poincaré sphere. Our scheme can also be extended to different gain media, which could lead to the creation of structured beams with richer wavelength, offering a promising platform for innovative studies on multidimensional light-field control.