Time-resolved measurements of cumulative effects in gas dynamics induced by high-repetition-rate femtosecond laser filamentation

IF 3.5 2区物理与天体物理 Q2 PHYSICS, APPLIED

Applied Physics Letters Pub Date : 2025-04-29 DOI:10.1063/5.0258907

Robin Löscher, Malte C. Schroeder, Alan Omar, Clara J. Saraceno

引用次数: 0

Abstract

The advent of high-average-power, ultrafast ytterbium-based lasers allows us to generate laser filaments at repetition rates ranging from tens of kHz up to hundreds of kHz. At such high-repetition rates, the inter-pulse time lies below the time required for the total diffusion of the deposited heat by each laser pulse, leading to cumulative hydrodynamic effects. Here, we present experimental time-resolved measurements of these dynamics in air for laser repetition rates between 1 and 100 kHz. We measure the change in the air refractive index caused by the localized heat deposition and the length of the filament-generated plasma channel, with which we can infer the corresponding change in air density. We observe that at repetition rates above 10 kHz, stationary density depletions with vanishing dynamics emerge. Our findings are of wide relevance for the fields of high-repetition-rate laser filamentation and its applications as well as THz generation from laser-induced plasma sources.

查看原文本刊更多论文

高重复率飞秒激光成丝引起的气体动力学累积效应的时间分辨测量

高平均功率、超快镱基激光器的出现，使我们能够以几十kHz到几百kHz的重复频率产生激光细丝。在如此高的重复频率下，脉冲间时间低于每个激光脉冲沉积热的总扩散所需的时间，从而导致累积的流体动力学效应。在这里，我们提出的实验时间分辨测量这些动态在空气中激光重复率在1和100千赫之间。我们测量了局部热沉积引起的空气折射率的变化和灯丝产生的等离子体通道的长度，由此可以推断出相应的空气密度变化。我们观察到，在重复频率高于10 kHz时，出现了动态消失的平稳密度耗尽。我们的发现对于高重复率激光丝化及其应用以及激光诱导等离子体源产生太赫兹具有广泛的意义。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Applied Physics Letters 物理-物理：应用

CiteScore

6.40

自引率

10.00%

发文量

1821

审稿时长

1.6 months

期刊介绍： Applied Physics Letters (APL) features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, APL offers prompt publication of new experimental and theoretical papers reporting applications of physics phenomena to all branches of science, engineering, and modern technology. In addition to regular articles, the journal also publishes invited Fast Track, Perspectives, and in-depth Editorials which report on cutting-edge areas in applied physics. APL Perspectives are forward-looking invited letters which highlight recent developments or discoveries. Emphasis is placed on very recent developments, potentially disruptive technologies, open questions and possible solutions. They also include a mini-roadmap detailing where the community should direct efforts in order for the phenomena to be viable for application and the challenges associated with meeting that performance threshold. Perspectives are characterized by personal viewpoints and opinions of recognized experts in the field. Fast Track articles are invited original research articles that report results that are particularly novel and important or provide a significant advancement in an emerging field. Because of the urgency and scientific importance of the work, the peer review process is accelerated. If, during the review process, it becomes apparent that the paper does not meet the Fast Track criterion, it is returned to a normal track.