InAs-doped silica films for saturable absorber applications

InAs-doped thin silica films having saturable absorption properties were fa bricated using rf sputtering. The films contain semiconductor nanoparticles preserving the zincblende crystal structure of bulk InAs. We have investig ated the linear and nonlinear optical as well as structural properties of t he films. Rapid thermal annealing in nitrogen was successfully used to tail or the optical absorption saturation dynamics. The films having saturable a bsorber properties were applied to Kerr lens mode locking initiation in a T i:Al2O3 laser resulting in self-starting mode locking operation with pulses as short as 25 fs. (C) 1999 American Institute of Physics. [S0003-6951(99) 00917-1].