论文标题
分子中飞秒时间分辨的四波混合信号的电场测量
Electric Field Measurement of Femtosecond Time-Resolved Four-Wave Mixing Signals in Molecules
论文作者
论文摘要
我们报告了一个实验，以测量从二氧化碳分子中光学三阶非线性相互作用发出的信号的飞秒电场。通过与飞秒近红外激光脉冲与tadpole的超弱飞秒脉冲测量技术结合使用的飞秒近近红外激光脉冲的混合，我们在相互作用的脉冲之间的不同时间延迟中测量了时间域中的非线性信号电场。发现从发射的非线性信号的时间阶段提取的chiRP敏感地取决于对非线性响应的电子和旋转贡献。尽管旋转贡献导致非线性信号的呼叫接近输入脉冲的chirp，但电子贡献导致呼叫明显更高，随着时间延迟的变化。我们的工作表明，电场分辨的非线性光谱法提供了有关超快时间尺度上非线性相互作用的详细信息。
We report an experiment to measure the femtosecond electric field of the signal emitted from an optical third-order nonlinear interaction in carbon dioxide molecules. Using degenerate four-wave mixing with femtosecond near infrared laser pulses in combination with the ultra-weak femtosecond pulse measurement technique of TADPOLE, we measure the nonlinear signal electric field in the time domain at different time delays between the interacting pulses. The chirp extracted from the temporal phase of the emitted nonlinear signal is found to sensitively depend on the electronic and rotational contributions to the nonlinear response. While the rotational contribution results in a nonlinear signal chirp close to the chirp of the input pulses, the electronic contribution results in a significantly higher chirp which changes with time delay. Our work demonstrates that electric field-resolved nonlinear spectroscopy offers detailed information on nonlinear interactions at ultrafast time scales.
