Abstract

In experiments with passing a colliding pulse mode-locking (CPM) light pulse through a nonlinear medium LiF color center crystal, we find that, for an ultrashort pulse (~10-ps duration, 1.06-μm wavelength), the durations become slightly shorter when it passes through a LiF color center crystal of 1- and 3-mm thickness. The duration increases when it passes 54.5 and 68 mm (increasing ~6-7 ps). We measured the other parameters of CPM pulses passing through a LiF crystal with the following results: The pulse number of the train, pulse energy, and the duration of the whole pulse train decrease with increasing LiF crystal length. The pulse interval becomes slightly shorter, but it is not relative to the crystal length. We believe that these phenomena can be explained by the saturable character and nonlinear refractive-index property of the light intensity passing through a nonlinear medium. Conversely, we demonstrate the existence of a nonlinear refractive-index property when the light intensity acts on the LiF color center crystal.

© 1986 Optical Society of America