Karampitsos Nikolaos, Kyrginas Dimitrios, Couris Stelios
Opt Lett. 2020 Apr 1;45(7):1814-1817. doi: 10.1364/OL.389309.
In this work, the nonlinear optical (NLO) response of some graphene dispersions is investigated under low (i.e., 10 Hz) and high (i.e., 80 MHz) repetition rate femtosecond (fs) laser excitation conditions, using ${Z}$Z-scan, optical Kerr effect (OKE), and a combination of ${Z}$Z-scan and thermal lensing techniques. It is shown, that the NLO response of graphene dispersions is negligible under low repetition rate fs laser excitation, while it becomes very large under high repetition rate laser excitation. In the latter case, it is shown that the observed very large NLO response arises entirely from thermal cumulative effects.
在本工作中，利用 $Z$ 扫描、光学克尔效应（OKE）以及 $Z$ 扫描与热透镜技术相结合的方法，研究了某些石墨烯分散体在低（即10 Hz）和高（即80 MHz）重复频率飞秒（fs）激光激发条件下的非线性光学（NLO）响应。结果表明，在低重复频率飞秒激光激发下，石墨烯分散体的NLO响应可忽略不计，而在高重复频率激光激发下，其NLO响应变得非常大。在后一种情况下，结果表明观察到的非常大的NLO响应完全源于热累积效应。
