抄録
X-ray free electron lasers (XFELs) have opened new frontiers in broad research fields because of
its unique properties; high brilliance, short pulse-duration, and high spatial coherence. Optical lasers with ultra-
high powers have also been applied in variety of scientific fields particularly in high energy density science.
Combinative use of XFELs and ultra-high power lasers provides novel capabilities to excite and diagnose ultra-
fast phenomena within small spatial scales under extreme conditions.
