An Orbital-Angular-Momentum- and Wavelength-Tunable 2 μm Vortex Laser
Xinmiao Zhao,
Jingliang Liu,
Mingming Liu,
Ruobing Li,
Luan Zhang,
Xinyu Chen
Affiliations
Xinmiao Zhao
Jilin Key Laboratory of Solid Laser Technology and Application, College of Physics, Changchun University of Science and Technology, Changchun 130022, China
Jingliang Liu
Jilin Key Laboratory of Solid Laser Technology and Application, College of Physics, Changchun University of Science and Technology, Changchun 130022, China
Mingming Liu
Jilin Key Laboratory of Solid Laser Technology and Application, College of Physics, Changchun University of Science and Technology, Changchun 130022, China
Ruobing Li
Jilin Key Laboratory of Solid Laser Technology and Application, College of Physics, Changchun University of Science and Technology, Changchun 130022, China
Luan Zhang
Jilin Key Laboratory of Solid Laser Technology and Application, College of Physics, Changchun University of Science and Technology, Changchun 130022, China
Xinyu Chen
Jilin Key Laboratory of Solid Laser Technology and Application, College of Physics, Changchun University of Science and Technology, Changchun 130022, China
In this paper, dual tuning of orbital angular momentum (OAM) and the wavelength of a Tm:YLF vortex laser was realized by off-axis pumping and F-P etalon. The tuning of Hermite–Gaussian (HG) modes by off-axis pumping was theoretically analyzed. In the experiment, the highest 17th order HG17,0 mode was realized by off-axis pumping. The threshold power increased from 2 to 17.51 W with the increase in off-axis distance, and the curve of threshold power vs. off-axis distance was partially consistent with the theoretical simulation analysis. The Laguerre–Gaussian (LG) modes carrying OAM were produced by mode converter, and the beam quality of LG modes was good. The phase distribution of the LG modes was verified by interference. Subsequently, an F-P etalon was inserted into the resonant cavity to tune the wavelength. Finally, the OAM tuning of the vortex beam from LG1,0(OAM = −1ℏ) to LG16,0(OAM = −16ℏ) was realized, and the corresponding wavelength tuning range was from 1898–1943 nm to 1898–1937 nm.
