Efficient XUV Harmonics Generated from Picosecond Laser Pulse Interactions withSolid Targets

摘要

The authors have observed harmonic orders up to the 67th at 15.7 nm in firstorder diffraction with indications of up to the 75th harmonic in second order signal which were created during the interaction of a 2.5 picosecond, 1053 nm laser pulse with a solid target for irradiances of 1.0 x 10 to the 19th power W micrometer square centimeter to the minus 2 power. The dependence of both the number of harmonics and their energy conversion efficiency with intensity have been explored. The authors have shown that there is little difference in the harmonic spectra between both s and p polarizations of the laser beam and with the addition of a pre-pulse. The power into the high harmonics is comparable to the output power of saturated collisional X-UV lasers at similar wavelengths. The authors have observed high coherence, high power and short wavelength output. These properties, together with the simplicity of selecting the required wavelengths, make these harmonics from the solid surface interacting with intense short laser pulses one of the most promising and competitive sources for applications. (Coyright (c) Council for the Central Laboratory of the Research Councils 1996.)