Ultrafast nonlinear photoresponse of single-wall carbon nanotubes: a broadband degenerate investigation. Issue 17 (18th April 2016)

• Record Type: Journal Article
• Authors: Xu, Shuo; Wang, Fengqiu; Zhu, Chunhui; Meng, Yafei; Liu, Yujie; Liu, Wenqing; Tang, Jingyi; Liu, Kaihui; Hu, Guohua; Howe, Richard C. T.; Hasan, Tawfique; Zhang, Rong; Shi, Yi; Xu, Yongbing
• Is Part Of: Nanoscale. Volume 8:Issue 17(2016)
• Page Start: 9304
• Page End: 9309
• Publication Date: 2016-04-18
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c6nr00652c
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The nonlinear optical response of a single-wall carbon nanotube composite is characterized across 600–2400 nm, revealing new spectral signatures of saturable absorption. Abstract : Understanding of the fundamental photoresponse of carbon nanotubes has broad implications for various photonic and optoelectronic devices. Here, Z -scan and pump–probe spectroscopy performed across 600–2400 nm were combined to give a broadband 'degenerate' mapping of the nonlinear absorption properties of single-wall carbon nanotubes (SWNTs). In contrast to the views obtained from non-degenerate techniques, sizable saturable absorption is observed from the visible to the near-infrared range, including the spectral regions between semiconducting excitonic peaks and metallic tube transitions. In addition, the broadband mapping unambiguously reveals a photobleaching to photoinduced absorption transition feature within the first semiconducting excitonic band ∼2100 nm, quantitatively marking the long-wavelength cut-off for saturable absorption of the SWNTs investigated. Our findings present a much clearer physical picture of SWNTs' nonlinear absorption characteristics, and help provide updated design guidelines for SWNT based nonlinear optical devices.