High-power lasers and their applications

Through the development of tuneable high-power and short-pulse laser systems atomic and molecular physics has recently been enriched with new tools for laser/atom interaction experiments at high optical field intensities and at short wavelengths. Experiments requiring ultra-intense laser radiation have recently become much more practical through the development of chirped pulse amplification. By using titanium sapphire as the gain medium, very compact and high-repetition rate systems reaching terawatt power levels can be constructed. Within the Lund High Power Laser Facility we operate such a system (100 fs, 2.0 TW, 10 Hz, tuneable 760-840 nm), which is being employed in basic and applied studies requiring high optical powers. On the more basic side, detailed studies of high-harmonics generation in jets of inert gas are being performed and spectrally well adapted harmonics radiation is also being applied in atomic physics experiments. Detailed studies of ionisation of atoms and fragmentation of molecules are also being pursued. Studies of X-ray laser generation are being made. By focusing high-power radiation in water or onto a high-nuclear-charge metal, white light generation and continuum hard X-rays are generated, respectively, being of considerable importance for applications. Thus, white laser light has been used for time-resolved studies of photon propagation in body tissues, leaves and paper sheets, while hard X-rays have been employed in emerging medical X-ray applications. © 1998 Academic Press Inc.