运用四阶Runge-Kutta法直接求解非线性介质内椭圆高斯光束传播方程组的方法分析增益介质内的克尔透镜（Kerr-lens）效应，结合在增益介质外运用的线性3456矩阵寻找自洽解，对半导体可饱和吸收镜（SESAM）启动的高功率KLM钛宝石激光器谐振腔的像散、稳定性、光束参数、自聚焦效应和克尔自聚焦强度与腔参数的关系进行了系统的理论计算。计算结果与实验结果相符合。该计算为SESAM启动的五镜腔KLM激光器的设计和调整提供了理论依据。

实现了低抽运三镜腔自锁模掺钛蓝宝石激光器的自锁模运转，对该激光嚣的自锁模区进行了实验研究，并对象散、稳定性、光束参量和克尔自聚焦强度与腔参量的关系进行了系统的理论计算该计算为自锁模固体激光器的设计和调整提供了理论依据。

给出非布儒斯特角情况下四棱镜组二阶、三阶色散的解析表示，并给出改变入射角和入射波长以及棱镜顶角对二阶、三阶色散的影响。

In this article we propose a theoretical treatment of noncollinear phase-matched femtosecond parametric interaction process pumped by ultrashort optical pulses, and investigated the pulse characteristics of OPG in BBO crystal. The results show that the major factors, which a8ect the optical parametric conversion coe9cient and durations of the pulses, are the group velocity mismatch and the phase mismatch among the three ultra-short pulses. In addition, the material dispersion can cause the durations of the pulses to increase when pump pulse is below 20 fs, and its in:uence becomes more obvious at low pump intensity.

In this paper, we investigate the group velocity matching based on tilting pulse front in type-III collinear phasematching configuration in BBO crystal. The design seems simple and practicable.

In this paper, we theoretically investigated the characteristics of the noncollinear phase-matched optical parametric amplifiers (OPA) system (NOPA) eeded by a white-light continuum. The results of our calculation demonstrate that the OPA system will be very sensitive to the exact noncollinear angle and the chirp of the seed pulse derived from white light continuum generation. For a sub-10 fs regime, GVM becomes a major detrimental factor and pre-compressing white light will weaken its influence.

We describe oscillating loops in a laser cavity and optical paths in a laser crystal of different wavelength rays for a four-mirror cavity Kerr-lens mode-locked laser. The relation between different wavelength ray paths and laser resonator parameters is deduced. The analytical expressions of second- and thirdorder dispersion including angular dispersion of the crystal are presented. The variations of group-delay dispersion (GDD) and third-order dispersion (TOD) with cavity parameters are calculated exactly. The calculation shows that GDD and TOD increase rapidly when the spacing between two folding mirrors approaches the boundary of a cavity stability zone. The rapid dispersion increase influences the modelocked pulse width and the mode-locked stability.

We have theoretically analyzed the characteristics of an optical parametric amplifier system seeded by an optical parametric generation. We investigated the influences of the energy, pulse duration, material dispersion, and the third-order nonlinear effect in β-barium borate. The group-velocity mismatch (GVM) becomes the most important factor for the amplification of bandwidths. Even though tilting the wave front of the pump can decrease the GVM, it seems impossible to generate pulses smaller than 10-fs with 400-nm pumping. However, 10-fs pulses can be achieved with a 30-fs pump duration with pumping at 800nm.

We present analytical expressions of quadratic and cubic phases in a three-element resonator for Kerrlens mode locking. Variation of quadratic and cubic phases with wedge angles of Ti: sapphire and apex angles of a prismatic output coupler are calculated. The results provide a theoretical basis for the design of a three-element cavity.

We present a novel high-power, self-starting mode-locked Ti: sapphire laser with a semiconductor saturable-absorber mirror as the starter element. This laser, whose slope efficiency is 22%, generates pulses with an average power as high as 1.7 W and a pulse width as short as 16 fs. The self-starting process is also investigated.