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.