HERCULES laser, which takes up several rooms at the University of Michigan's Center for Ultrafast Optical Science, is the most intense repetitive laser in existence. HERCULES's laser beam's power is concentrated to a micron speck about 100th the diameter of a human hair.
HERCULES's design is based on chirped-pulse amplification. The Petawatt stage of HERCULES was activated in 2007 and reached power of 300 TW. The output beam with this power after the adaptive optics is focused to approximately 1 micron spot size using high numerical aperture parabolic mirror producing unprecedented intensity of 2x10^22 W/cm^2 but for duration of only 30 fs (1 fs=10^-15 s). The HERCULES power will be gradually increased to 500 TW by the end of 2008.
HERCULES laser is used for generating relativistic plasmas including "table top" acceleration of relativistic electrons using plasma waves; for generating high quality energetic ion beams; for developing efficient x-ray and neutron sources; and, for investigating phenomena related to producting fusion energy using ultra-intense lasers.
Researchers, all from the University of Michigan, include Karl Krushelnick and Yanovsky , co-principal investigators, Vladimir Chvykov, and Galina Kalinchenko.
HERCULES Press Release, University of Michigan News Service
"HERCULES Petawatt Laser," College of Engineering, University of Michigan