Institut fïr Physikalische Chemie, Karlsruhe Institute of Technology (KIT), D-76128 Karlsruhe, Germany.
Opt Lett. 2011 Aug 15;36(16):3188-90. doi: 10.1364/OL.36.003188.
We report on femtosecond pump-probe experiments on two different photoinitiators in solution. These two molecules have recently appeared as attractive candidates for far-field optical lithography based on stimulated-emission-depletion (STED) inspired approaches aiming at beating Abbe's diffraction limit. For the case of 7-diethylamino-3-thenoylcoumarin (DETC), we find that stimulated emission clearly dominates over excited-state absorption, whereas the opposite holds true for the case of isopropylthioxanthone. We argue that it is desirable that stimulated emission dominates over excited-state absorption as depletion mechanism in STED photoresists. Thus, DETC is an attractive corresponding photoinitiator.
我们报告了在溶液中的两种不同光引发剂的飞秒泵浦探测实验。这两种分子最近作为基于受激辐射损耗（STED）启发的方法的远场光学光刻的有吸引力的候选物出现，旨在突破阿贝衍射极限。对于 7-二乙氨基-3-噻吨酰基香豆素（DETC）的情况，我们发现受激辐射明显优于激发态吸收，而异丙基噻吨酮的情况则相反。我们认为，作为 STED 光致抗蚀剂的耗尽机制，受激辐射优于激发态吸收是理想的。因此，DETC 是一种有吸引力的相应光引发剂。
