Generation of a coherent x ray in the water window region at 1 kHz repetition rate using a mid-infrared pump source

We demonstrate the generation of a coherent x ray in the water window region in a gas cell filled with neon gas using a wavelength-tun able mid-IR femtosecond laser operating at 1 kHz repetition rate. The cutoff energy and conversion efficiency of the water window x ray can be optimized by tuning gas pressure as well as the focal position. (C) 2009 Optical Society of America