Author: Sakae, T.
Paper Title Page
TUP060 Potential Photochemical Applications of the Free Electron Laser Irradiation Technique in Living Organisms 505
  • F. Shishikura, K. Hayakawa, Y. Hayakawa, M. Inagaki, K. Nakao, K. Nogami, T. Sakai, T. Tanaka
    LEBRA, Funabashi, Japan
  • T. Kii, H. Ohgaki, H. Zen
    Kyoto University, Kyoto, Japan
  • T. Sakae
    Nihon University School of Dentistry at Matsudo, Matsudo-shi, Japan
  In 2001, the Laboratory for Electron Beam Research and Application (LEBRA) achieved the first lasing of 0.9–6.5 microns near-infrared free electron lasers (FELs), in which higher harmonics were generated by using nonlinear optical crystals. Following this breakthrough, we have paid considerable attention to LEBRA-FEL’s potential for investigating photochemical reactions in living organisms. We have established a micro-irradiation technique using an optical fiber connected to a fine tapered glass rod of <5 microns in diameter, enabling FEL irradiation of a single cell and even the inner organelles of live cells. We then verified that visible LEBRA-FEL light can control the germination of lettuce seeds, a well-known photochemical reaction, and determined that red light (660 nm FEL) promotes germination and far-red light (740 nm FEL) inhibits it. Here, we summarize the efficiency of various visible wavelengths of LEBRA-FEL light, ranging from 0.4–0.8 microns, for regulating photoreactions in lettuce seeds and we also summarize the efficiency of infrared wavelengths up to 20 microns, which can be generated by combined use of the LEBRA-FEL and the Kyoto University FEL.
We thank the staff of Prof. T. Morii (Institute of Advanced Energy, Kyoto Univ.) for helpful assistance.