Efficient X-ray short pulse generation from femtosecond laser-produced plasma for pump-probe spectroscopy

X-rays emitted from high-density plasmas created by femtosecond laser pulses are of great interest. Since such X-rays are synchronized to the laser pulse, these sources in the short pulse regime are expected to provide high temporal resolution in X-ray diffraction, absorption spectroscopy, and other applications used to measure the dynamic processes in optically excited materials. In this paper, we describe our experimental results on efficient X-ray short pulse generation from plasma created on a solid target by a femtosecond laser pulse. Using a picosecond soft X-ray pulse from femtosecond laser-produced plasma, we demonstrate time-resolved soft X-ray absorption measurements in optically excited silicon near the L_II,III absorption edge by means of pump-probe spectroscopy