Tuesday, March 11, 2003
Modern Optics and Spectroscopy Seminar, MIT (Cambridge, MA)
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 living cells. In this talk I will review recent results obtained in the field of femtosecond micromachining. I 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. I will also discuss a number of applications in the fabrication of micro-optical devices and in biology and medicine.