Intense visible white-light pulse generation in gas-filled hollow-core fibers pumped by Yb-lasers for multi-color time-resolved spectroscopy

由 Yb 激光器泵浦的充气空心光纤中产生强烈的可见白光脉冲，用于多色时间分辨光谱

• 批准号: 569169-2021
• 负责人: Razzari, Luca
• 金额: $ 6.56万
• 依托单位: Institut national de la recherche scientifique
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=720795
• 关键词: Intense; visible; white; light; pulse

Ultrashort, high-energy laser pulses have delivered unprecedented capabilities in driving and probing ultrafast dynamics in various materials and nowadays represent the cornerstone of a multitude of research fields in modern science. However, despite the three decades of progress of laser frequency conversion and amplification technology, the generation of energetic few-cycle visible white light (VIS-WL) pulses (wavelength: 400-800 nm) is still very challenging. Such pulses are regarded as an essential tool for the temporal investigation of e.g., biological energy transfer processes and photo-generated charge carrier dynamics in semiconductors. Current technology typically requires extremely complex alignment and apparatus that lower the conversion efficiency and deteriorate the beam quality. Also, the maximum achievable pulse energy is limited in such systems, due to the damage threshold of the employed nonlinear crystals. In this context, gas-filled hollow-core fibers (HCF) represent an appealing alternative nonlinear platform, as they accommodate high-energy pulses and provide a straightforward spectral extension, together with excellent output beam characteristics. Prof. Razzari's group at INRS-EMT has recently obtained a promising preliminary result of ultrafast VIS-WL pulse formation in an HCF pumped by ytterbium (Yb) laser pulses. The thorough investigation of this novel VIS-WL generation mechanism in an HCF and its exploitation into a marketable setup are the key target of this project. To achieve these goals, an overall team of 1 PhD student and 2 postdocs, helped by 2 intern students every year, will work on the project full time. These personnel will be supervised by Prof. Razzari and will closely interact with our industrial partner (few-cycle Inc.). Eventually, our partner company will be able to introduce an affordable and customizable multi-color system relying on an industrial-grade Yb laser to study the response of a variety of materials on ultrafast time-scales, thus allowing a large number of academic and industrial labs to have access to a technology currently available only in a handful of top-notch research centers around the world.

超短高能激光脉冲在驱动和探测各种材料的超快动力学方面提供了前所未有的能力，如今代表了现代科学众多研究领域的基石。然而，尽管激光变频和放大技术取得了三十年的进步，但高能少周期可见白光（VIS-WL）脉冲（波长：400-800 nm）的生成仍然非常具有挑战性。这种脉冲被认为是半导体中生物能量转移过程和光生载流子动力学等时间研究的重要工具。当前的技术通常需要极其复杂的对准和设备，这会降低转换效率并恶化光束质量。此外，由于所采用的非线性晶体的损坏阈值，此类系统中可实现的最大脉冲能量受到限制。在这种情况下，充气空心光纤（HCF）代表了一种有吸引力的替代非线性平台，因为它们可容纳高能脉冲并提供直接的光谱扩展以及出色的输出光束特性。 INRS-EMT 的 Razzari 教授团队最近获得了在镱 (Yb) 激光脉冲泵浦的 HCF 中形成超快 VIS-WL 脉冲的有希望的初步结果。对 HCF 中这种新颖的 VIS-WL 生成机制的彻底研究及其在市场化设置中的开发是该项目的主要目标。为了实现这些目标，由 1 名博士生和 2 名博士后组成的整体团队，每年在 2 名实习生的帮助下，将全职从事该项目。这些人员将受到 Razzari 教授的监督，并将与我们的工业合作伙伴（few-cycle Inc.）密切互动。 最终，我们的合作伙伴公司将能够推出一种经济实惠且可定制的多色系统，依靠工业级镱激光器来研究各种材料在超快时间尺度上的响应，从而使大量的学术和工业实验室能够获得目前只有世界各地少数顶尖研究中心才能提供的技术。