High-repetition rate tunable laser system for low-noise measurements in nanophotonics

为了在可见光和近红外光谱的纳米光子学领域建立新的研究路线，我们需要一个强大的、高度可调谐的、重复频率高达几十兆赫兹的脉冲激光源。这将使我们能够在低噪声水平下进行测量，这在我们的超快实验室中目前可用的系统是不可能的。新的光源将与实验室现有的基础设施相结合，特别是干涉脉冲压缩系统和共聚焦显微镜装置，可以在单纳米结构水平上进行实验。新研究的两个特殊例子是光子到声表面波的能量转换领域，以及单光子发射器（如纳米钻石）与混合纳米光子谐振器的耦合。计划中的实验需要高平均激发功率，在整个可见和近红外光谱上的广泛可调性，以及高重复率，以便能够用比暗噪声水平高几个数量级的信号进行测量。我们将使用新激光系统的其他研究领域是混合纳米结构的非线性光子学领域，包括等离子体和介电材料以及二维结构。首选的激光系统具有高平均功率，350至4000 nm波长的广泛可调性，以及各种泵浦/探头配置的高度灵活性。

In order to establish new research lines in the area of nanophotonics in the visible and near-infrared part of the spectrum we need a powerful and highly tunable pulsed laser source with a high repetition rate of dozens of MHz. This will enable us to conduct measurements with a low noise level, which is not possible with the current systems available in our ultrafast laboratory. The new light source will be coupled with existing infrastructure available in this lab, particularly an interferometric pulse compression system and a confocal microscope setup, which enables experiments at single nanostructure level. Two particular examples of newly enabled research are in the areas of energy conversion from photons to acoustic surface waves, and in the coupling of single-photon emitters such as nanodiamonds with hybrid nanophotonic resonators. The planned experiments necessitate high average excitation powers, wide tunability over the whole of the visible and near-infrared spectrum, and a high repetition rate, in order to allow measurements with a signal several orders of magnitude above the dark noise level. Additional research fields where we will use the new laser system are in the area of non-linear photonics of hybrid nanostructures, consisting of both plasmonic and dielectric materials as well as 2D structures. The preferred laser system has as distinguishing factors a high average power, broad tunability from 350 to 4000 nm wavelength, and a high flexibility for various pump/probe configurations.