Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, UK.
Sci Rep. 2017 Mar 15;7:44488. doi: 10.1038/srep44488.
Far-field spectroscopy and mapping of electromagnetic near-field distribution are the two dominant tools for analysis and characterization of the electromagnetic response in nanophotonics. Despite the widespread use, these methods can fail at identifying weak electromagnetic excitations masked by stronger neighboring excitations. This is particularly problematic in ultrafast nanophotonics, including optical sensing, nonlinear optics and nanolasers, where the broad resonant modes can overlap to a significant degree. Here, using plasmonic metamaterials, we demonstrate that coherent spectroscopy can conveniently isolate and detect such hidden high-order photonic excitations. Our results establish that the coherent spectroscopy is a powerful new tool. It complements the conventional methods for analysis of the electromagnetic response, and provides a new route to designing and characterizing novel photonic devices and materials.
远场光谱学和电磁近场分布的映射是分析和表征纳米光子学中电磁响应的两种主要工具。尽管应用广泛，但这些方法在识别被更强的相邻激发所掩盖的弱电磁激发时可能会失效。在超快纳米光子学中，包括光学传感、非线性光学和纳米激光器中，这种情况尤其成问题，其中宽共振模式可以在很大程度上重叠。在这里，我们使用等离子体超材料证明了相干光谱学可以方便地分离和检测这种隐藏的高阶光子激发。我们的结果表明，相干光谱学是一种强大的新工具。它补充了传统的电磁响应分析方法，并为设计和表征新型光子器件和材料提供了新途径。
