Watt-level 1173 nm Laguerre-Gaussian mode generation from a self-Raman Nd:GdVO₄ laser

We demonstrate a high power (watt-level) self-Raman Nd:GdVO ₄ Laguerre-Gaussian (LG) mode laser by employing an off-axis needle-pumping geometry. The system selectively produces right- or left-handed LG modes by adjusting the off-axis displacement of the pump beam relative to the laser cavity. The maximum output power of the generated 1173 nm LG beam (corresponding to the first-Stokes emission of from the 882 cm ^-1 Raman shift) reaches 1.2 W for an absorbed pump power of 8.6 W. Furthermore, the system enables the generation of a watt-level bottle beam, formed by the coherent superposition of Gaussian and radial LG modes.