Livermore fires u𨔅-terawatt laser
After an initial firing on August 1, a 100-TW-class laser developed at Lawrence Livermore National Laboratory (LLNL, Livermore, CA) as part of its three-year, $10 million Petawatt Laser Project is claimed to be the world`s most powerful laser. Using chirped pulse amplification, researchers modified a single beam from LLNL`s Nova Nd:glass laser to produce 125 TW of average power in a pulse shorter than 0.5 ps. This is 3000 times shorter than a pulse from Nova, which uses 10 beams to produce 120 TW. In operation, the laser`s Ti:sapphire front end amplifies the Nova beam to 50 mJ/pulse at 1054 nm. The beam then passes through Nd:glass rod amplifiers and a 9-cm disk amplifier, further increasing the energy density to 75 J/pulse. Finally, the beam travels into a double-pass pulse compressor, resulting in a 125-TW beam (10-20 W/cm2) with 420-fs pulsewidths and 55 J/pulse energy density.
Michael Perry, petawatt-project head, says the terawatt laser is "only a warm-up" for the petawatt laser, which is expected to be 10 to 20 times more powerful. Its initial testing is scheduled for next January. "Our ultimate goal is to achieve 1021 W/cm2 (1000 terawatts) of power," says Mike Campbell, LLNL associate director for lasers. "We want an enormously high-brightness laser that will give us very, very high intensities to do a range of fundamental science not possible before, especially in relativistic plasma physics."