LF Group, ILE, Osaka Univ.

22/07/2026

Bana and Zhong have completed their master thesis presentation.👏

12/07/2026

Fujioka-san will give a talk at the symposium.

大阪商工会議所のセミナー・イベント等を掲載しています。

19/06/2026

2026年7月3日に開催される日本学術会議国際光デー記念シンポジウムにて、藤岡さんが講演します。

19/06/2026

Sasaki-san and Tanaka-san attended the EUVL and Source Workshop 2026, held at UC Berkeley in California from June 8 to 11—the leading conference on EUV (Extreme Ultraviolet) lithography, where the latest research spanning the full scope of EUVL, from light sources to exposure systems, is presented and the field's near- and long-term future is debated by researchers from top institutions and companies worldwide. Japan's K-program, an EUV lithography initiative launched just a year ago, was represented by more than ten participants, and our group's results drew strong interest from attendees both in Japan and abroad. Beyond the technical program, the Bay Area offered rare clear weather and memorable views of San Francisco Bay—including the Golden Gate Bridge, Alcatraz, and the UC Berkeley campus—seen from Lawrence Berkeley National Laboratory (Berkeley Lab), where we stayed at the Guest House and where Tanaka-san had spent nearly a year as a visiting researcher during her Ph.D., making the trip a nostalgic return.

10/06/2026

Our collaboration with Princeton University and the Princeton Plasma Physics Laboratory (PPPL) is now published.

"Time-Resolved Interferometric Measurements of Plasma Density Evolution in Laser-Driven Capacitor-Coil Targets"

Using the University of Osaka's LFEX laser, we mapped how plasma builds up around laser-driven capacitor-coil targets—devices used to generate strong magnetic fields for magnetic reconnection studies. Time-resolved interferometry revealed two distinct sources loading the coil region.

🔗

Laser-driven capacitor-coil targets provide a compact platform for generating strong magnetic fields and are widely used in magnetized high-energy-density (HED)

05/06/2026

Fujioka-san and Takizawa-san visited Livermore, CA, U.S., for participating a workshop.

05/06/2026

New preprint has been posted on ArXiv.
https://arxiv.org/abs/2606.05948

Practical requirements such as improving wall-plug efficiency and reducing system footprint have become increasingly important with the introduction of extreme ultraviolet (EUV) lithography into high-volume semiconductor manufacturing. These demands motivate the development of solid-state mid-infrared lasers as alternatives to current CO2 lasers. Systematic exploration of laser-to-EUV conversion efficiency (EUV-CE) over a broad parameter space is essential when altering the drive laser's wavelength, because the EUV-CE depends on the laser parameters in a complex manner. In this work, we performed a large-scale grid search of more than 140,000 parameter combinations for laser-produced tin plasma EUV sources using the radiation-hydrodynamics code STAR-1D, which is validated against EUV source experiments. The systematic wavelength dependence of the optimum pulse width and target size is governed by the requirement to simultaneously achieve the electron temperature and density optimal for EUV emission, maintain efficient laser absorption, and suppress EUV self-absorption. The resulting CE map predicts a global maximum of 5.63% at 5.5 {\mu}m. For the practically relevant 2 {\mu}m solid-state driver, a maximum CE of 4.64% is obtained, in good agreement with recent experimental results. Multiple operating points are identified over a broad range of pulse parameters, providing guidance for 2 {\mu}m-driven EUV source development.

Practical requirements such as improving wall-plug efficiency and reducing system footprint have become increasingly important with the introduction of extreme ultraviolet (EUV) lithography into high-volume semiconductor manufacturing. These demands motivate the development of solid-state mid-infrar...

13/05/2026

New preprint has been posted on ArXiv.
https://arxiv.org/pdf/2605.09191

In laser-driven fusion, one of the trickiest questions has been: what are the high-energy protons actually doing inside the target? Normal detectors only catch protons that escape — and those get scrambled by intense plasma fields on the way out. Our team came up with a clever workaround: let the target itself be the detector. As protons race through a boron target, they trigger tiny amounts of nuclear reactions that leave behind "fingerprints". By measuring those fingerprints after each shot, we can reconstruct the proton energy distribution inside the target — and count the proton–boron fusion reactions directly. We tested it on the kJ-class laser at Osaka, and it works even in setups where conventional diagnostics fail. A new window into what's really happening inside laser fusion targets!

18/04/2026

This is a message for those who understand Japanese.

電験・エネ験試験受験者に人気の雑誌「電気計算」の2026年5月号に藤岡さんの執筆の解説記事が掲載されました。

レーザ技術は、さまざまな分野での応用が進んでおり、その重要性はますます高まっている。レーザ技術は私たちの身近なところでも多く使用されている技術だが、レーザって何？ どんなところで使われているのかと疑問.....

03/04/2026

We held a welcome party for new members under the full-bloom cherry blossoms at Expo Commemoration Park. Three new members joined our group in April.