Two-photon absorption induced polymerization provides a powerful method for the fabrication of intricate three-dimensional
microstructures. Recently, Lucirin TPO-L was shown to be a photoinitiator with several advantageous properties for two-photon
induced polymerization. Here we measure the two-photon absorption cross-section spectrum of Lucirin TPO-L, which presents
a maximum of 1.2 GM at 610 nm. Despite its small two-photon absorption cross-section, it is possible to fabricate excellent
microstructures by two-photon polymerization due to the high polymerization quantum yield of Lucirin TPO-L. These results
indicate that optimization of the two-photon absorption cross-section is not the only material parameter to be considered
when searching for new photoinitiators for microfabrication via two-photon absorption.
PACS 42.65.-k; 78.40.Me; 42.70.Jk; 81.05.Lg