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研究了酞菁铜薄膜的吸收光谱和飞秒三阶非线性光学极化率 χ( 3 ) .酞菁铜薄膜吸收光谱Q带的分裂是由于分子间相互作用导致酞菁的大π电子环产生畸变 ,从而使eg(LUMO)轨道的二重简并度解除 .分别采用钛宝石激光器的振荡级和放大级输出 ,用z 扫描方法测量了酞菁铜的三阶非线性光学极化率 .用激光器振荡级测量的 χ( 3 ) 值为 - 4 3× 10 -7esu ,而用激光器放大级测量的结果为 2 6 2× 10 -11esu ,前者比后者大 4个量级 .酞菁铜薄膜对激光束的吸收以及振荡级激光脉冲的高重复频率表明振荡级测量的结果主要来自热致透镜效应的贡献 ,而采用低重复频率的放大级测量得到的值才真正反映酞菁铜薄膜的本征三阶非线性光学特性
The absorption spectra and the third-order non-linear optical susceptibilities χ (3) of copper phthalocyanine films were investigated.The absorption bands of copper phthalocyanine films were caused by the large π electron ring of phthalocyanine due to the intermolecular interactions Distortion, so that the dual degeneracy of eg (LUMO) orbit can be canceled.The third-order nonlinear optical polarizability of copper phthalocyanine has been measured by z-scan method using the output of oscillating stage and amplification stage of Ti: sapphire laser respectively The value of χ (3) measured by the laser oscillation level was -4 3 × 10 -7 esu, while the measurement by the laser amplification stage was 2 6 2 × 10 -11 esu, the former being 4 orders of magnitude larger than the latter. The copper phthalocyanine film The absorption of the laser beam and the high repetition rate of the laser pulse at the oscillating stage indicate that the result of the oscillation level measurement mainly comes from the contribution of the thermal lensing effect while the value measured by the amplification stage of the low repetition frequency truly reflects the present case of the copper phthalocyanine film Third-order nonlinear optical characteristics