Direct generation of 523 nm orbital Poincare mode from a diode-pumped Pr3+:LiYF4 laser with an off-axis optical needle pumping geometry

We demonstrate an ultra-compact (8 mm-long) green orbital Poincare Pr3+:LiYF4 (YLF) laser, in which the intracavity lasing modes are represented as eigenmodes on an equivalent orbital Poincare sphere (eOPS). This is achieved through the simple application of an 'optical-needle' pumping geometry in conjunction with off-axis laser mode-manipulation. Optical vortices that are produced and mapped on north and south poles of the eOPS exhibit a maximum output power of 304 mW with a pump-to-laser-output slope efficiency of 12%. In addition, higher-order structured modes, including Ince Gaussian (IG), helical IG (HIG), Hermite-Laguerre Gaussian (HLG) and vortex lattices, can be directly generated from the laser cavity. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

An ultra-compact green orbital Poincare Pr3+:LiYF4 laser demonstrates high output power and efficiency through unique pumping geometry and laser mode manipulation. This laser system is able to generate higher-order structured modes directly from the cavity, showcasing its versatility and capabilities.