文章基本信息

标题：Ultrasensitive nonlinear absorption response of large-size topological insulator and application in low-threshold bulk pulsed lasers
本地全文：下载
作者：Jin-Long Xu ; Yi-Jian Sun ; Jing-Liang He 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
DOI：10.1038/srep14856
出版社：Springer Nature
摘要：Dirac-like topological insulators have attracted strong interest in optoelectronic application because of their unusual and startling properties. Here we report for the first time that the pure topological insulator Bi₂Te₃ exhibited a naturally ultrasensitive nonlinear absorption response to photoexcitation. The Bi₂Te₃ sheets with lateral size up to a few micrometers showed extremely low saturation absorption intensities of only 1.1 W/cm² at 1.0 and 1.3 μm, respectively. Benefiting from this sensitive response, a Q-switching pulsed laser was achieved in a 1.0 μm Nd:YVO₄ laser where the threshold absorbed pump power was only 31 mW. This is the lowest threshold in Q-switched solid-state bulk lasers to the best of our knowledge. A pulse duration of 97 ns was observed with an average power of 26.1 mW. A Q-switched laser at 1.3 μm was also realized with a pulse duration as short as 93 ns. Moreover, the mode locking operation was demonstrated. These results strongly exhibit that Bi₂Te₃ is a promising optical device for constructing broadband, miniature and integrated high-energy pulsed laser systems with low power consumption. Our work clearly points out a significantly potential avenue for the development of two-dimensional-material-based broadband ultrasensitive photodetector and other optoelectronic devices.