Multiphoton fabrication of functional three-dimensional structures

Abstract

Multiphoton absorption (MPA), by virtue of its optical nonlinearity, can be caused to occur efficiently only within the tight focal volume of a laser beam. As a result, it is possible to localize any photochemical or photophysical process that depends upon MPA within a small region of space, the position of which can be controlled readily. The phenomenon has been used to great advantage in 3-D imaging over the past decade [1], and more recently has been applied to 3-D microfabrication, particularly in the form of photopolymerization [2-4]. When chemical nonlinearity is present in addition to optical nonlinearity, it is even possible to fabricate features that are considerably smaller than the diffraction limit [5].