High-power Ytterbium femtosecond laser amplifier system

高功率镱飞秒激光放大器系统

• 批准号: 532577495
• 金额: --
• 依托单位: Technische Universität Dortmund
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2024
• 资助国家: 德国
• 起止时间: 2023-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/532577495?language=en
• 关键词: power; Ytterbium; femtosecond; laser; amplifier

One of the research foci of my group is nonlinear THz spectroscopy of cavity quantum electrodynamical (c-QED) structures and novel materials. Our recently improved cavity designs have enabled extreme light-matter coupling strengths with light-matter hybridized states extending over as many as six optical octaves simultaneously, from < 0.1 THz to > 6 THz. As a next step, we seek to investigate the nonlinear polarization dynamics of these structures which is expected to include mixing of polariton modes beyond the normal-mode approximation, the generation of non-classical light, dynamical squeezing and entanglement of polariton modes as well as the generation of vacuum radiation. The large spectral range and multi-mode nature of extremely strong coupling requires a new approach to two-dimensional strong-field spectroscopy providing THz pulses which simultaneously feature several features that are difficult to unite: strong electric field amplitudes on the order of several 100 kV/cm, short durations close to the single-cycle limit and gap-free, ultrabroadband spectra. With the requested equipment, we will implement a new generation of 2D THz spectroscopy by combining several only recently established approaches for THz generation. The approach is based on an Yb femtosecond laser amplifier system delivering ultrashort pulses centred at a wavelength of 1030 nm, pulse energies of up to several mJ, and tuneable repetition rates ranging from 100 kHz to the MHz range. The light source features remarkably low noise levels approaching 10^-3 of relative pulse-to-pulse energy fluctuations, excellent pulse energy scalability, and high long-term reliability. The laser power will be split into three parts: a weak pulse which serves for electro-optic detection and two strong ones which are individually switched on a pulse-to-pulse basis by acousto-optic modulators at a rate of up to half the repetition rate. This unique design enables fast modulation on the order of 1 MHz, greatly exceeding the commonly employed kHz-rate modulation achieved by mechanical means, and correspondingly, provides exceptionally low noise levels. Further measures to optimize the signal-to-noise ratio of our system include custom-cut detection electronics based on FPGA technology developed in our group, as well as optical beam stabilization systems. In order to achieve the required THz bandwidth, the laser pulses will be compressed to < 50 fs by Heriott-cell based, multi-pass, multi-plate continuum generation and chirp compensation. Broadband THz strong-field generation will subsequently be performed using water-cooled, large-area spintronic emitter structures which provide single-cycle THz strong-field pulses with a gap-free spectrum extending from 0.1 THz up to > 10 THz – an unprecedentedly broad spectral range for two-dimensional strong-field spectroscopy which will open up new vistas for nonlinearities in the THz range.

我组的研究重点之一是腔量子电动力学（C-AQED）结构和新型材料的非线性THZ光谱。我们最近改进的腔设计已经实现了极端的轻度耦合强度，而光杂交状态延伸了多达六个光学八度，从<0.1 thz到> 6 thz。在下一步中，我们试图研究这些结构的非线性极化动力学，预计将包括超出正常模式近似值的极性模式的混合，非古典光的产生，北极星模式的动态挤压和纠缠以及真空辐射的产生。极强耦合的较大频谱范围和多模式性质需要采用新的方法来实现二维强场光谱，从而提供THZ脉冲，这些脉冲提供了几个难以团结的功能：在几个100 kV/cm的订单上，强烈的电场放大器，几个短时间的短期，接近单个循环效果和易于限制的，超级效果，超级范围，超级效果。借助请求的设备，我们将通过结合最近建立的THZ生成方法来实施新一代的2D THZ光谱。该方法基于YB飞秒激光放大器系统，其以1030 nm的波长为中心的超短脉冲，脉冲能达到多个MJ，可调性重复速率从100 kHz到MHz范围。光源具有明显的低噪声水平，接近相对脉冲到脉冲能量波动的10^-3，出色的脉冲能量可伸缩性和高长期可靠性。激光功率将分为三个部分：用于电磁检测的弱脉冲和两个强的脉冲，它们通过声学调节器以高达一半的重复率的速度单独切换为脉冲到脉冲基础。这种独特的设计实现了1 MHz阶的快速调制，极大地超过了通过机械手段实现的通常带有的KHz速率调制，并且相应地提供了异常低的噪声水平。进一步优化系统的信噪比的措施包括基于我们组中开发的FPGA技术的定制检测电子设备以及光束稳定系统。为了获得所需的THZ带宽，激光脉冲将通过基于Heriott-Cell的，多通，多板连续产生和CHIRP补偿来压缩到<50 fs。随后将使用水冷的大面积旋转发射极结构进行宽带THZ强场生成，这些发射极发射极结构可提供单周期THZ强场脉冲，并具有无间隙光谱从0.1 Thz延伸到10 thz的频谱 - 最前提的宽光谱范围是二维强度的范围，这将是一个不合时宜的范围。