KU-FEL (Kyoto University Free Electron Laser) is a free electron laser (FEL) facility at Institute of Advanced Energy, Kyoto University, Japan. 

Mission of KU-FEL facility is providing intense and wavelength-tunable infrared laser beams to energy related research and developments.

There are two light sources based on electron accelerators. 

#1: Mid-Infrared FEL (MIR-FEL): intense and wavelength tunable MIR laser in the wavelength region from 3.4 to 26 micro-meter. 

#2: THz coherent Undulator Radiation (THz-CUR) source: intense and frequency-tunable THz laser in the frequency region from 0.16 to 0.6 THz. 

Those light sources are open to external users for various application experiments.

In parallel with the user experiments, R&Ds of MIR-FEL and THz-CUR are actively performed in KU-FEL facility.

News

• • March 5th 2025

Heishun Zen, a staff member of KU-FEL won the "Nishikawa Prize" given by the Foundation for High Energy Accelerator Science for his contribution on "Development of Mid-Infrared Free Electron Laser for Advanced Application Research".

• • July 13th 2023

Thanks to the replacement of the vacuum window for MIR-FEL extraction and replacement of undulator vacuum dact for narrower undulator gap, the MIR-FEL performance was improved. Now the "Wavelength vs Macro-pulse Energy" graph of MIR-FEL was updated.

• • June 5th 2023
            User operation of KU-FEL in FY2023 started. In this fiscal year, 17 external user groups will use KU-FEL for their own researches under the ZE program.

  • June 20th 2022

User operation of KU-FEL in FY2022 started. In this fiscal year, 18 external user groups will use KU-FEL for their own researches under the ZE program.

• • June 8th 2022

Thanks to the radiation shield enforcement, the maximum electron beam power of KU-FEL was upgraded from 41.2 to 60.0 W.

• • June 4th 2021

Heishun Zen, a staff member of KU-FEL won the "Young Researcher Award of the Japanese Society of Infrared Science and Technology" for his achievement of MIR-FEL development and effort for application researches.

• • May 26th 2021

An article written by Heishun Zen (KU-FEL) with coauthors was selected as the Highlights of 2020  collection for Applied Physics Express (APEX) and the Japanese Journal of Applied Physics (JJAP).

• May 11th 2021

One of KU-FEL users Mr. Yohei Tanaka won the "Student Presentation Award of the Physical Society of Japan" of the 76th annual meeting for his research using KU-FEL.

• Mar. 4th 2021

One of KU-FEL users, Mr. Yohei Tanaka won the "Best presentation award" of the 41st annual meeting of the Laser Society of Japan" for his research using KU-FEL.

• Dec. 10th 2020

One of KU-FEL users, Mr. Yohei Tanaka won the "Best presentation award" of the Beam Physics Young Scientist Workshop 2020 for his research using KU-FEL.

• Nov. 9th 2020

Heishun Zen, a staff member of KU-FEL was selected as a winner of the 15th (2021) young scientist award of the Physical Society of Japan.

• Oct. 11th 2020

The latest article written by Heishun Zen (KU-FEL) with coauthors ranked first in the most read article of Applied Physics Express for 744 downloads in 10 days after its publication.

• Oct. 1st. 2020

The article written by Heishun Zen (KU-FEL) with coauthors was selected as a "Spotlights" article of Applied Physics Express. (screen shot)

• Sep. 2020

One of KU-FEL users, Mr. Yohei Tanaka won the "Best presentation award" of the laser summer school 2020 for his research using KU-FEL.

• May 2019

An article written by Kyohei Yoshida (one of KU-FEL users) with coauthors won "The 5th Best Paper Award of Journal of the Japan Society of Infrared Science and Technology" for his research using KU-FEL.

Research Highlights

• Investigating the Laser-Induced Periodic Surface Structure (LIPSS) on Silicon Jan. 10th 2023

• Record High Efficiency of Free Electron Laser Oscillator, Contributing to Strong Field Physics in LWIR (in Japanese)  Oct. 8th 2020

• Towards a Green Future: Efficient Laser Technique Can Convert Cellulose into Biofuel Jun. 23rd 2020