Nonlinear X Ray Wave Mixing

Today nonlinear optics is primary focused on the infrared to the visible regimes In this spectral range concepts and techniques based on nonlinear optics are implemented in many diverse fields For example laser technology optical communication ultrafast science quantum optics and nonlinear spectroscopy techniques The high brightness and peak power of the new xray free electron lasers has opened the possibilities of performing novel experiments in the field of nonlinear optics at very short wavelengths and of extending concepts from the optical regime into the x ray regime X ray nonlinearities are very