The goal of this research project is to develop a tunable EUV radiation source using high-order harmonic generation (HHG). The high-order harmonics will be generated in a gas-filled capillary waveguide using a Ti:Sapphire laser producing 35 fs pulses. Efficient high order harmonic generation requires phase matching and pressure tuning is used for the capillary system. The capillary inner radius will be optimized for a maximum drive laser pulse energy of about 7 mJ. Coherent control of the driver laser is used to study the influence of drive laser pulse on the HHG process.
To reach shorter wavelength, we are also investigating high-order harmonic generation from an ionized noble gas instead of neutral atoms. Since pressure tuning is not possible any more, we are investigating quasi-phase matching techniques to improve the efficiency of HHG from noble gas ions, in particular we are looking into ion density modulation techniques.