Ultrabroadband tunable femtosecond lasersystem

拟议的飞秒激光系统将被用作三种不同类型实验的激光源，从而显着扩大了研究小组的实验可能性：1。在现有的FTIR显微镜光谱仪上开发用于三维激光光刻的材料（基于聚合物的光敏材料、用于直接金属印刷的材料、用于渗透的吸收和非线性材料）作为明亮的光源。为此，必须对波长高达8 µm、亮度高、噪声低的指纹进行表征。这允许识别所涉及的化学反应。2.用于铁磁和反铁磁材料的时间分辨泵浦探测光谱，以研究这些材料中的光子-磁振子转换过程。将进行近红外泵浦和太赫兹探测实验以及太赫兹泵浦和光学探测实验。特别感兴趣的是实验，允许发射太赫兹辐射后，强烈的近红外脉冲相比，光学声子的共振激发。为此，激光系统必须能够处理高达20 µm（15 THz）的波长，并且还必须提供脉冲持续时间< 50 fs的强脉冲输出，这允许通过自旋电子太赫兹发射器产生1-40 THz的宽带太赫兹脉冲。3.用于三维光子结构的空间分辨光谱学，以识别无序样品中的模式分布，并以角分辨率表征具有拓扑特性的样品。除此之外，三维光子晶体中2-4微米的外尔点目前正在进行光谱分析。

The proposed femtosecond laser system will be used as a laser source for three different types of experiments, thus significantly expanding the experimental possibilities of the research group: 1. to develop materials for three-dimensional laser lithography (polymer-based photosensitive materials, materials for direct metal printing, absorbing and non-linear materials for infiltration) as a brilliant light source on an existing FTIR microscope spectrometer. For this purpose the fingerprint range up to 8 µm wavelength with high brilliance and low noise has to be characterized. This allows the identification of the chemical reactions involved.2. for time-resolved pump-probe spectroscopy on ferro- and antiferromagnetic materials to study the photon-magnon conversion processes in these materials. NIR pump and THz probe experiments as well as THz pump and optical probe experiments will be performed. Of particular interest are experiments that allow the emission of THz radiation after an intense NIR pulse compared to the resonant excitation of optical phonons. For this purpose, the laser system must be able to address wavelengths up to 20 µm (15 THz) and must also provide an output with intense pulses with a pulse duration < 50 fs, which allows the generation of broadband terahertz pulses of 1-40 THz via spintronic terahertz emitters.3. for spatially resolved spectroscopy of three-dimensional photonic structures to identify the mode distribution in disordered samples and to characterize samples with topological properties with angular resolution. Among other things, Weyl points in three-dimensional photonic crystals, which are at 2-4 µm, are currently to be spectroscopied.