Thursday, February 26, 2004
Physics Colloquium, University of Missouri-Columbia (Columbia, MO)
When femtosecond laser pulses are focused tightly into a transparent material, the intensity in the focal volume can become high enough to cause nonlinear absorption of laser energy. The absorption, in turn, can lead to permanent structural or chemical changes. Such changes can be used for micromachining bulk transparent materials. Applications include data storage and the writing of waveguides and waveguide splitters in bulk glass, fabrication of micromechanical devices in polymers, and subcellular photodisruption inside single cells. In this talk we will review recent results obtained in the field of femtosecond micromachining. We will discuss the thresholds for permanent structural change for a variety of materials to obtain information on the underlying mechanisms that are responsible for optical breakdown in the bulk of a transparent sample. We will also present recent results in the micromanipulation of subcellular organelles in live cells.