Titanium-sapphire femtosecond laser amplifier system

Lange教授小组要求的激光放大器系统提供了持续时间为35 fs、脉冲能量为4.5 mJ、中心波长为800 nm、重复频率为3 kHz的超短光脉冲。使用激光器的基本，强太赫兹（THz）脉冲，仅由一个单一的振荡周期，并与超过1 MV/cm的峰值字段将产生倾斜的脉冲前沿光学整流。此外，强，锁相中红外脉冲峰值场高达100 MV/cm和可调的中心频率范围从15至100太赫兹将产生使用所要求的双光学参量放大器。时域光谱同时跟踪太赫兹脉冲的振幅和相位将使线性表征以及强场测量，包括振幅分辨，二维光谱。此外，一个定制的切割磁铁低温恒温器系统，在一个单独的提案中要求，将使光谱在磁场和低温temperature.Our小组调查光物质相互作用的极端限制，其中光学非线性发生在时间尺度上显着短于一个单一的光周期。最近的成就包括动态布洛赫振荡和高次谐波产生的观察，拓扑绝缘体中狄拉克电子的光波加速，强天线增强的太赫兹近场对自旋的最小耗散切换，超越科恩定理的非微扰非线性，和非绝热开关的深强光-所要求的激光系统将使我们能够继续这项研究，并探索凝聚态系统中太赫兹子循环物理的新方向。最近的腔量子电动力学（cQED）实验已经利用光学谐振器的真空模式来控制电子输运，化学反应或超导性。虽然这些研究都集中在强或超强的光-物质耦合平衡，我们将研究一般的高场动力学，特别是以前无法访问的耦合强度，真空拉比频率超过光的振荡周期。为此，我们将进一步提高我们建立的腔耦合朗道电子的耦合强度，研究深强耦合半导体子带间跃迁的非线性，并探索cQED的新概念，包括超导谐振器或原子薄的电子系统，如过渡金属二硫属化物。当我们系统地探索从线性到非线性再到非微扰动力学的转变时，我们期待着大量的新现象，包括高阶非线性、非经典光的产生、非线性相互作用产生的新共振和相变。子循环解析将在解开相关量子动力学中发挥关键作用。

The laser amplifier system requested by the group of Prof. Lange provides ultrashort optical pulses with a duration of 35 fs, a pulse energy of 4.5 mJ, a center wavelength of 800 nm, and a repetition rate of 3 kHz. Using the laser’s fundamental, strong terahertz (THz) pulses consisting only of a single oscillation cycle, and with peak fields exceeding 1 MV/cm will be generated by tilted pulse-front optical rectification. Moreover, strong, phase-locked mid-infrared pulses with peak fields of up to 100 MV/cm and tuneable center frequencies ranging from 15 to 100 THz will be generated using the requested dual optical parametric amplifier. Time domain spectroscopy tracing the amplitude and phase of THz pulses simultaneously will enable linear characterization as well as strong-field measurements including amplitude-resolved, two-dimensional spectroscopy. In addition, a custom-cut magnet cryostat system, requested in a separate proposal, will enable spectroscopy at magnetic fields and cryogenic temperatures.Our group investigates extreme limits of light-matter interaction in which optical nonlinearities occur on time scales significantly shorter than a single cycle of light. Recent achievements include the observation of dynamical Bloch oscillations and high-harmonics generation, lightwave acceleration of Dirac electrons in topological insulators, minimally dissipative switching of spins by strong, antenna-enhanced THz near fields, non-perturbative nonlinearities beyond Kohn’s theorem, and non-adiabatic switching of deep-strongly light-matter coupled electrons in specialized THz resonators.The requested laser system will allow us to continue this research and explore novel directions of THz subcycle physics in condensed matter systems. Recent experiments in cavity quantum electrodynamics (cQED) have utilized the vacuum modes of optical resonators to control electronic transport, chemical reactions, or superconductivity. While these studies have focused on strong or ultrastrong light-matter coupling in equilibrium, we will investigate high-field dynamics in general, and in particular for previously inaccessible coupling strengths, where the vacuum Rabi frequency exceeds the oscillation period of light. To this end, we will further boost the coupling strength of our established cavity-coupled Landau electrons, investigate nonlinearities of deep-strongly coupled semiconductor intersubband transitions, and explore novel concepts for cQED including superconducting resonators or atomically thin electronic systems such as transition metal dichalcogenides. As we systematically explore the transition from linear to nonlinear to non-perturbative dynamics, we expect a wealth of novel phenomena including high-order nonlinearities, generation of non-classical light, novel resonances generated by nonlinear interactions, and phase transitions to unfold. Subcycle resolution will play a key role in unravelling the relevant quantum dynamics.