基于离轴泵浦与腔外模式转换的高阶可调谐厄米-高斯与拉盖尔-高斯激光研究OA

[Background]Hermite-Gaussian(HG)beams are fundamental orthogonal solutions of stable optical resonators,and their efficient conversion to Laguerre-Gaussian(LG)vortex beams provides an effective way to generate high-order vortex light.However,the direct intracavity generation of LG beams commonly suffers from chiral superposition and poor controllability,which limits its practical applications.[Purpose]This paper aims to propose a scheme to achieve high-order tunable HG and LG laser output with stable chiral control,to address the chiral superposition problem of directly generated LG beams.[Methods]An 808 nm fiber-coupled laser diode was used to pump the Nd:YVO4 crystal in a plano-concave resonator.The pitch and tilt angles of the input mirror were precisely adjusted to realize off-axis pumping.A π/2 astigmatic mode converter composed of a pair of cylindrical lenses was adopted for external-cavity mode conversion.The orbital angular momentum and chirality of LG beams were verified by a Mach-Zehnder interferometer.[Results]Continuously tunable HG0,n(1st to 68th order)and HG1,n(1st to 46th order)modes were obtained.The HG modes were efficiently converted into LG0,1 to LG0,68 vortex beams.The chiral symmetry flipping of LG0,1/LG0,-1 and LG0,68/LG0,-68 was realized by reversely adjusting the input mirror angles.[Conclusions]The proposed scheme combines the high-order tunability of HG modes and the chiral controllability of LG modes without intracavity chiral elements,providing a flexible and reliable technical approach for the practical application of high-order vortex lasers.