High repetition rate high power laser system for mid-IR experiments

我的研究目标是控制复杂量子材料与超短光脉冲相互作用的宏观性质。通过这一提议，我们将建立一种新的光谱学，在实验上解决在定制的低温电磁环境中样品的中红外振动和电子模式的共振激发的关键问题。我们将实现一个多维泵浦和探测装置，能够测量复杂量子材料在振动、电子或磁性质的低能模式的多个共振驱动下的光导随时间的演变。在这里，我提出了一种新的光谱方法，能够测量介电函数在从3 eV(400 Nm)到0.1 eV(0.015 mm)的较宽能量范围内的微小变化，随后在中红外范围内进行多次激发。为了在中红外和可见光中产生足够的激光脉冲，我们将购买一种能够以高重复频率(50 KHz)发射超短高能脉冲(每脉冲能量&1.5mJ)的激光系统。光源产生的激光脉冲应分为四个脉冲，一个用于产生太赫兹脉冲(在1028 nm处)，以及3个泵浦光学参数放大器(OPA)，其设计用于产生可在可见光和中红外范围内调谐的本征同步脉冲。具体来说，OPA是：1)双OPA和差频产生，以产生可在5-20M(EPP&>1微焦耳，5-15微米)之间调谐的CEP中红外OPA；2)在=2微米到10微米的中IR OPA，EPP&GT；1微焦耳在所有范围内；3)可见OPA，可在600-900 nm(脉冲持续时间&lt；30fs)之间可调。该激光系统将提供可独立调谐的中红外脉冲，能够共振地驱动低能激发，如声子模、电子能隙(超导和CDW)和自旋激发。这样的来源将成为旨在通过多个光激发控制超导的实验的基础。该研究单位将能够在40千赫的单次激发下测量大波长范围(从400到10000纳米)的光激发反应。高重复率可见光脉冲的整形将使基于随机的光谱与中红外激发方案成为可能。

My research goal is to control of the macroscopic properties of complex quantum materials in interaction with ultrashort light pulses. Through this proposal we will establish a novel spectroscopy to address experimentally key aspects on the resonant excitation of mid-IR vibrational and electronic modes for samples in a tailored cryogenic electromagnetic environment. We will implement a multidimensional pump and probe setup capable to measure the time evolution of the optical conductivity of complex quantum materials subsequently to the multiple resonant drive of low energy modes of vibrational, electronic or magnetic nature. In detail here I propose a novel spectroscopic approach capable of measuring small changes in the dielectric function on a broad energy range from 3eV (400nm) to 0,1eV(0,015mm) subsequently to multiple excitation in the mid-IR range. In order to produce adequate laser pulses in the mid-IR and visible we will purchase a laser system capable of delivering ultrashort high energy pulses (energy per pulse>1.5mJ) at high repetition rate (50KHz). The laser pulse produced by the source should be divided into four pulses, one used to generate THz pulses (at 1028 nm), and 3pumping optical parametric amplifiers (OPA) designed to produce intrinsically synchronized pulses tuneable in the visible and mid-IR range. In detail the OPA are: 1) Twin OPA and difference frequency generation to generate CEP mid-IR pulses tuneable between 5-20m (Epp>1µJ from 5 to 15µm); 2) Mid-IR OPA from =2µm to 10µm with Epp>1µJ on all the range; 3) Visible OPA tuneable between 600 and 900nm (pulse duration<30fs). The laser system will deliver independently tuneable mid-IR pulses capable of resonantly drive low energy excitations such as phonon modes, electronic gaps (superconducting and CDW) and spin excitation. Such a source will be the back bone of experiments aimed at controlling the superconducting through multiple photo-excitations. The research unit will allow for the measurements of the response to photo-excitation on a large wavelength range (from 400 to 10000nm) single shot at 40KHz. The shaping of visible light pulses at high repetition rate will enable stochastic based spectroscopy with mid-IR excitations schemes.