Webster Scott, Reyes-Reyes Marisol, Williams Richard, Carroll David L
Center for Nanotechnology and Molecular Materials, Department of Physics, Wake Forest University, Winston-Salem, North Carolina, USA.
J Nanosci Nanotechnol. 2008 Dec;8(12):6470-3.
Using nonlinear absorption at 532 nm in the nanosecond temporal regime, we have measured the low fluence nonlinear transmittance properties of the reverse saturable absorbing carbocyanine dye, 1,1',3,3,3',3'-hexamethylindotricarbocyanine iodide (HITCI), blended with well dispersed carbon nanotubes. The nonlinear optical properties of the blends are strongly dependent on the ratio of dye to nanotubes in solution. In the case where the nanotubes per dye molecule ratio is large, we see a distinctive enhancement in optical fluence limiting properties of the system, suggesting enhanced absorption of the excited states. However, when the nanotube to dye ratio decreases, the system's response is dominated by the behavior of the dye. We suggest that this can be understood as a two component system in which sensitized dye molecules associated with the nanotubes have an effectively different optical cross-section from the dye molecules far from the nanotubes. From classical antennae considerations, this is expected.
利用纳秒时间尺度下532nm处的非线性吸收，我们测量了与充分分散的碳纳米管混合的反饱和吸收花菁染料1,1',3,3,3',3'-六甲基吲哚三碳菁碘化物（HITCI）的低能量密度非线性透过率特性。混合物的非线性光学特性强烈依赖于溶液中染料与纳米管的比例。在每个染料分子的纳米管比例较大的情况下，我们观察到系统的光能量密度限制特性有显著增强，这表明激发态的吸收增强。然而，当纳米管与染料的比例降低时，系统的响应由染料的行为主导。我们认为这可以理解为一个双组分系统，其中与纳米管相关的敏化染料分子与远离纳米管的染料分子具有有效不同的光学截面。从经典天线的角度考虑，这是可以预期的。
