Wavy lines in two-photon photopolymerization microfabrication

We present experimental results on the changes of lines in two-photon photopolymerization microfabrication. Polymerized lines remain straight, become wavy, and even float away with increased focus height as the sample is moved closer to the focusing lens. The influence of the focus height, the incident laser energy, and the scan speed was studied. The lower the incident energy or the faster the scan speed, the more easily the lines become wavy. From the focus height at which the lines become wavy and float away, we can estimate the lateral and longitudinal size of a voxel. (C) 2004 Optical Society of America.