Formation of the micro-sized grains under influence of the nanosecond laser pulses
Formation of the micro-sized grains under influence of the nanosecond laser pulses
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纳秒激光脉冲影响下微米颗粒的形成
DOI：
10.1007/s10853-007-2327-x
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发表时间：
2008
影响因子：
4.5
通讯作者：
I. Kityk
中科院分区：
文献类型：
--
作者：
R. Miedzinki;J. Ebothé;M. Oyama;I. Kityk
在10 ns 1,064 nm激光脉冲的照射下，在ITO衬底上沉积了纳米银颗粒，发现了周期约为3.2μm、调制高度高达150 nm的周期性光致栅的出现。结果表明，ITO电阻起主要作用。这可以解释为两个相干波相互作用的结果。第一波是由基频激光产生的，第二波是由双光子吸收现象引起的。值得一提的是，仅通过有效泵浦功率低于0.7GW/cm2的10 ns激光脉冲处理才能获得观察到的光致光栅。由于激光功率密度明显低于飞秒激光，脉冲持续时间比飞秒激光大，这一结果的产生可能归因于等离子体激发导致了进一步的热电离。
The occurrence of a periodic photo-induced grating having about 3.2-μm period and modulation heights up to 150 nm is discovered here under the irradiation of 10-ns 1,064-nm laser pulses with Ag nano-particles deposited on ITO substrates. It is shown that the main role is played by the ITO resistance. This can be explained as the result of interaction between two coherent waves. The first wave is engendered by the fundamental laser and the second one is due to the two-photon absorption phenomenon. It is important mentioning that the observed photo-induced grating is obtained only from a treatment by single 10-ns laser pulses with an effective pump power below 0.7 GW/cm2. Since the laser power densities are markedly low and the pulse durations larger than those of the femtosecond laser, the origin of this result is expected to be ascribed to the plasmon excitation leading to further thermoionization.