2017 年 59 巻 1 号 p. 34-38
Recent X-ray free electron lasers(XFEL) open new scientific field of broad area. Quantum optics in hard x ray photon are one of the advanced field of them. Specially, after success of XFEL pumped Kα laser, many quantum processes come within the range of research and scientific applications. In this article, simple physical model for understanding these activities is introduced with actual experimental results. Prospect of next possibilities is also briefly mentioned.