双离轴泵浦Yb:CALGO激光器中的波长可调厄米-高斯模式和轨道角动量可调涡旋光束

Wavelength-tunable Hermite-Gaussian modes and an orbital-angular-momentum-tunable vortex beam in a dual-off-axis pumped Yb:CALGO laser.

作者信息

Shen Yijie, Meng Yuan, Fu Xing, Gong Mali

出版信息

Opt Lett. 2018 Jan 15;43(2):291-294. doi: 10.1364/OL.43.000291.

DOI:10.1364/OL.43.000291

Abstract

A dual-off-axis pumping scheme is presented to generate wavelength-tunable high-order Hermite-Gaussian (HG) modes in Yb:CaGdAlO lasers. The mode and wavelength can be actively controlled by the off-axis displacements and pump power. The purities of the output HG modes are quantified by intensity distributions and the measured M values. The highest order reaches m=15 for stable HG mode, and wavelength-tunable width is about 10 nm. Moreover, through externally converting the HG modes, the vortex beams carrying orbital angular momentum (OAM) with a large OAM-tunable range from ±1ℏ to ±15ℏ are produced. This work is effective for largely scaling the spectral and OAM tunable ranges of optical vortex beams.

摘要

提出了一种双离轴泵浦方案，以在Yb:CaGdAlO激光器中产生波长可调谐的高阶厄米-高斯（HG）模式。模式和波长可通过离轴位移和泵浦功率进行主动控制。输出HG模式的纯度通过强度分布和测量的M值进行量化。对于稳定的HG模式，最高阶数达到m = 15，波长可调谐宽度约为10 nm。此外，通过外部转换HG模式，产生了携带轨道角动量（OAM）的涡旋光束，其OAM可调谐范围从±1ℏ到±15ℏ。这项工作对于大幅扩展光学涡旋光束的光谱和OAM可调谐范围是有效的。