深圳大学电子科学与技术学院：《激光原理 Principle of Laser》课程教学资源（PPT课件）第二章 开放式光腔与高斯光束 第六部分 非稳腔的几何自再现波型

§2.10非稳腔的几何自再现波型 Operation in the stable regime has been shown to lead to narrow gaussian beams This situation is not compatible with the need for high-power output that requires large lasing volumes The nature of the coupling results in an output beam with a large aperture that is consequently well collimated without the use of telescoping optics

§2.10 非稳腔的几何自再现波型 •Operation in the stable regime has been shown to lead to narrow Gaussian beams. This situation is not compatible with the need for high-power output that requires large lasing volumes. •The nature of the coupling results in an output beam with a large aperture that is consequently well collimated without the use of telescoping optics

非稳腔( unsta ble optical resonators 的构成 双凸腔:R1g2>1,gg2>1 平凸腔:R1,g2=1,!;g2>1 平凹非稳腔RD,R20,g2L,g10 或R+R2

一、非稳腔(unstable optical resonators)的构成 双凸腔： 平凸腔： 平凹非稳腔 双凹非稳腔 R1  0,R2  0, g1 1, g2 1, g1 g2 1 R1  0,R2 → g1 1, g2 =1, g1 g2 1 1 2 1 2 R L R L g g     , , 0, 0 1 2 1 2 R L R L g g     , , 0, 0 1 2 1 2 R R L g g +   , 1 或 或 R L g   , 0

R/2+R2/2=L 特例:非对称实共焦腔2gg2=81+g2 两个凹面镜在腔内有一个公共实焦点,构成 个望远镜系统 山凸非稳腔 R0、R2L R1/2+R2/ 特例:虚共焦型非稳腔 g182=81+g2 凹面镜的实焦点与凸面镜的虚焦点相重合,公 共焦点在腔外,构成一个虚共焦望远镜系统

特例：非对称实共焦腔 两个凹面镜在腔内有一个公共实焦点，构成一 个望远镜系统 凹凸非稳腔 特例：虚共焦型非稳腔 凹面镜的实焦点与凸面镜的虚焦点相重合，公 共焦点在腔外，构成一个虚共焦望远镜系统 1 2 1 2 1 2 2 2 2 g g g g R R L = + + = 1 2 1 2 1 2 2 2 2 g g g g R R L = + + = 1 1 2 R L R R L  R R 1 2   0 0 、 非稳要求：或 + 

The advantages of the unsta ble resonator concept, when the necessary conditions are met then include Large and controllable. mode volume Controllable diffractive output coupling Good transverse mode discrimination automatically collimated output beams Ease of alignment and adjustment Efficient power extraction Good far-field beam patterns end

The advantages of the unstable resonator concept, when the necessary conditions are met, then include: • Large, and controllable, mode volume • Controllable diffractive output coupling • Good transverse mode discrimination • Automatically collimated output beams • Ease of alignment and adjustment • Efficient power extraction • Good far-field beam patterns end