标题：Theory of intracavity-frequency-doubled solid-state four-level lasers
作者：Zhang, XY; Wang, QP; Zhao, SZ; Li, JF; Li, P; Ren, C; Zheng, J
作者机构：[Zhang, XY; Wang, QP; Zhao, SZ; Li, JF; Li, P; Ren, C; Zheng, J]Shandong Univ, Sch Informat Sci & Engn, Jinan 250100, Peoples R China.;[Zh 更多
通讯作者地址：[Zhang, XY]Shandong Univ, Sch Informat Sci & Engn, Jinan 250100, Peoples R China.
来源：SCIENCE IN CHINA SERIES E-TECHNOLOGICAL SCIENCES
关键词：solid-state lasers; intracavity frequency doubling; laser theory
摘要：The spatial distributions of the pumping, the population inversion density, and the intracavity photon densities of the fundamental and the second harmonic are taken into account in the rate equations of the intracavity-frequency-doubled cw lasers. By normalizing the related parameters, it is shown that the general solution of these space-dependent rate equations is dependent upon three dimensionless parameters: the pump to laser-mode size ratio, the normalized pump level, and a parameter written as eta(SHG) which is related to the ability of the nonlinear crystal to convert the fundamental to the second harmonic. By numerically solving these rate equations, a group of general curves are obtained to express the relations between the solution and the three dimensionless parameters. In addition, the optimal pump to laser-mode size ratio and the optimal eta(SHG) are determined. A comparison with the result obtained under the plane-wave approximation is also given.