Barberoglou M, Gray D, Magoulakis E, Fotakis C, Loukakos P A, Stratakis E
Foundation for Research & Technology – Hellas, Institute of Electronic Structure and Laser P. O. Box 1527, Heraklion GR-71110, Greece.
Opt Express. 2013 Jul 29;21(15):18501-8. doi: 10.1364/OE.21.018501.
We demonstrate the capability to control the ripple periodicity on polycrystalline ZnO films by applying temporally delayed femtosecond double pulses. It is shown that there is a characteristic pulse separation time for which one can switch from low- to high- spatial-frequency ripple formation. Results are interpreted based on the relation of the characteristic delay time with the electron-phonon relaxation time of the material. Our results indicate that temporal pulse shaping can be advantageously used as a mean to control the periodic nanoripples' formation and thus the outcome of laser assisted nanofabrication process, which is desirable for the applications of nanopatterned transparent semiconductors.
我们展示了通过施加时间延迟的飞秒双脉冲来控制多晶ZnO薄膜上波纹周期性的能力。结果表明，存在一个特征脉冲间隔时间，在此时间可以从低空间频率波纹形成切换到高空间频率波纹形成。基于特征延迟时间与材料电子 - 声子弛豫时间的关系对结果进行了解释。我们的结果表明，时间脉冲整形可以有利地用作控制周期性纳米波纹形成的手段，从而控制激光辅助纳米制造过程的结果，这对于纳米图案化透明半导体的应用是可取的。
