Ultrasensitive nonlinear absorption response of large-size topological insulator and application in low-threshold bulk pulsed lasers

• DOI: 10.1038/srep14856
• Publication Date: 2015-10-07T06:41:33Z
• Authors: Jin-Long Xu; Yi-Jian Sun; Jing-Liang He; Yan Wang; Zhao-Jie Zhu; Zhen-Yu You; Jian-Fu Li; Mitch M. C. Chou; Chao-Kuei Lee; Chao-Yang Tu
• Keywords: Topological insulator; Photoexcitation; Pulse duration; Pulsed laser

Abstract 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 pure insulator Bi 2 Te 3 exhibited a naturally ultrasensitive nonlinear absorption response to photoexcitation. The sheets with lateral size up few micrometers showed extremely low saturation intensities only 1.1 W/cm at 1.0 1.3 μm, respectively. Benefiting from this sensitive response, Q-switching pulsed laser was achieved μm Nd:YVO 4 where threshold absorbed pump power 31 mW. This is lowest Q-switched solid-state bulk lasers best our knowledge. A pulse duration 97 ns observed an average 26.1 also realized as short 93 ns. Moreover, mode locking operation demonstrated. These results strongly exhibit promising optical device constructing broadband, miniature integrated high-energy systems consumption. Our work clearly points out significantly potential avenue development two-dimensional-material-based broadband photodetector other devices.