Takenaka Y, Nishimae J, Kuzumoto M, Yoshizawa K
Appl Opt. 1995 Jan 20;34(3):400-7. doi: 10.1364/AO.34.000400.
A novel cavity design based on a stable resonator configuration is presented. The output coupler of the new stable resonator has a circular partial-reflection region in the center that is surrounded by an antireflection region. This resonator operates in a large-volume TEM(00) mode that is mainly determined by the partial-reflection region of the output coupler and is characterized by the use of an additional laser beam that is spread from the optical path in the cavity because of diffraction and is amplified by a laser medium. By combining part of a beam transmitted from the partial-reflection region with the amplified diffraction beam, a laser beam having a large diameter is obtained. A diffraction-limited output beam with the M(2) factor of 1.3 is obtained, as predicted theoretically when the new stable resonator is applied to a high-power cw CO(2) laser.
提出了一种基于稳定谐振器配置的新型腔设计。新型稳定谐振器的输出耦合器在中心有一个圆形部分反射区域，该区域被一个抗反射区域包围。这种谐振器在大体积TEM(00)模式下工作，该模式主要由输出耦合器的部分反射区域决定，其特点是使用了一束额外的激光束，该激光束由于衍射而在腔内偏离光路，并被激光介质放大。通过将从部分反射区域透射的光束的一部分与放大的衍射光束相结合，可获得大直径的激光束。当将新型稳定谐振器应用于高功率连续波CO(2)激光器时，理论预测可获得M(2)因子为1.3的衍射极限输出光束。
