Measuring the spatio-temporal field of ultrashort pulses near nanostructures.

超短光脉冲与物质在纳米尺度上的相互作用在光电子学和纳米光子学中具有重要意义。超短脉冲在不同的频率范围内激发纳米结构材料，因此这些不同频率的场分布的结果叠加决定了实际的局域场演化。因此，控制照明激光脉冲的光谱相位提供了对飞秒时间尺度上局部光场的空间和时间演化的直接控制。然而，到目前为止，位于纳米尺度上的光场的时空动力学在真实空间和时间域中都是隐藏的，不能直接获得。在这个项目中，我们的目标是结合两种强大的技术，近场扫描光学显微镜和光谱干涉法，测量纳米结构内和周围具有纳米空间和飞秒时间分辨率的超弱飞秒脉冲的全时变光场。因为这项技术是线性的，所以它可以用于平均每个脉冲包含不到一个光子分数的极弱脉冲。这种极端的灵敏度在相干控制、纳米光学、量子信息和其他研究领域开辟了许多迷人的研究途径，这些领域以高空间和时间分辨率研究光和物质之间的相互作用。

The interaction of ultrashort pulses of light with matter on the nanoscale is of fundamental importance in optoelectronics and nanophotonics. Ultrashort pulses excite nanostructured materials over a wide range of different frequencies so that the resulting superposition of these field distributions, with different frequencies determines the actual local field evolution. Hence, controlling the spectral phase of the illuminating laser pulses offers direct control over the space and time-evolution of the local optical fields on femtosecond timescales. However, spatio-temporal dynamics of optical fields localized on the nanoscale has so far been hidden from direct access in both in real space and in the time domain. In this project we aim to combine two powerful techniques, near-field scanning optical microscopy and spectral interferometry, to measure full time-dependent optical fields in and around nanostructures for ultraweak femtosecond pulses with nanometer spatial and femtosecond temporal resolution. Because the technique is linear it can be used for extremely weak pulses that on average contain less than a fraction of a photon per pulse. This extreme sensitivity opens up many fascinating research avenues in coherent control, nano-optics, quantum information and other research fields that investigate the interaction between light and matter with high spatial and temporal resolution.