Coherent Sources of XUV Radiation

Extreme ultraviolet radiation (X-UV), also referred to as soft X-rays, offers very special optical properties. The X-UV refractive index of matter is such that normal reflection cannot take place on polished surfaces whereas beam transmission through one micrometer of almost all materials reduces to zero. Therefore, it has long been a difficult task to imagine and to implement devices designed for optical experiments in this wavelength range. After soft x-ray holography became available the use of X-UV radiation for interferometry, holography, diffractive optics, nonlinear radiation-matter interaction, time-resolved study of fast phenomena and many other applications, including medical sciences, is ubiquitous.