All-optical switchings of 3-hydroxyflavone in different solvents

• 来源期刊: 中国物理B（英文版）
• 关键词: all-optical switching 3-hydroxyflavone ESIPT nonlinear
• 年，卷（期）: 2008,（4）
• 页码范围: 1461-1466
• 页数: 6页
• 语种: 英文

摘要

3-hydroxyflavone (3-HF) is an organic molecule with an excited-stated intramoleculax proton transfer (ESIPT)effect. All-optical switchings and beam deflections of 3-HF in three kinds of solvents (cyclohexane, ethanol and dimethyl sulfoxide) have been investigated by using the third-haxmonic generation (355 nm) of a mode-locked Nd:YAG laser as a pump beam and a continuous-wave (cw) He-Ne laser (632.8 nm) as a probe beam. The nonlinear refractive indices of 3-HF in the three different solvents axe determined by using the Z-scan technique under an ultraviolet (UV) pump beam at a wavelength of 355 nm. It has been found that the optical switching and beam deflection effects result from the change in refractive index of 3-HF under the irradiation of the pump beam. On the basis of the analyses of absorption spectra and fluorescence spectra, we conclude that the change in refractive index of 3-HF is due to not the thermal effect but the ESIPT effect of 3-HF under the pump beam. As the ESIPT is exceedingly fast, 3-HF might be an excellent candidate for high-speed optical switching.