Thirugnanasambandam Manasadevi P, Senatsky Yuri, Ueda Ken-ichi
Institute for Laser Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan.
Opt Express. 2011 Jan 31;19(3):1905-14. doi: 10.1364/OE.19.001905.
We demonstrated the operation of cw diode-pumped Yb:YAG laser in radial or azimuthal polarized (RP or AP) beams using a combination of birefringent uniaxial crystal (c-cut YVO4 or α-BBO) and lens as intra-cavity elements. RP and AP doughnut modes (M2 = 2-2.5, polarization extinction ratio 50-100:1) with output power up to 60 mW were generated. Apart from doughnut modes, RP or AP ring-like off-axis oscillations and multi-ring beams with mixed RP and AP were also observed at the output of this laser scheme. Using intra-cavity short focus lenses with spherical aberrations AP or RP modes of higher orders was obtained. Mechanism of mode selection in the laser is discussed. The large variety of beams with axially symmetric polarizations from the output of the proposed laser scheme may find applications in different fields.
我们展示了连续波二极管泵浦Yb:YAG激光器在径向或方位角偏振（RP或AP）光束中的运行情况，使用双折射单轴晶体（c切割YVO4或α-BBO）和透镜的组合作为腔内元件。产生了输出功率高达60 mW的RP和AP空心模式（M2 = 2 - 2.5，偏振消光比为50 - 100:1）。除了空心模式外，在该激光方案的输出端还观察到RP或AP环状离轴振荡以及具有混合RP和AP的多环光束。使用具有球差的腔内短焦距透镜获得了高阶的AP或RP模式。讨论了激光器中的模式选择机制。所提出的激光方案输出的具有轴对称偏振的多种光束可能在不同领域找到应用。
