As of January 2009, the world's most powerful laser is the Texas Petawatt Laser at the University of Texas in Austin, US. In March 2008, the laser became the first in the world to surpass the 1 petawatt (million billion watts) threshold, a quantity of power about 60 times greater than the world's average energy consumption in 2004, which measured about 15 terawatts. The way that such tremendous power is attained is by only activating the laser for a very short amount of time, only one-tenth of a trillionth of a second. Though the total energy produced by the laser is small -- about 200 joules, or similar to that burned by a light bulb in a couple seconds -- it is released in such a minuscule portion of time that the power output per second (watts) is enormous.
Being the most powerful laser on Earth, the Texas Petawatt Laser is used by scientists to reproduce exotic conditions never seen on Earth -- like the interior or a supernova or the Sun. Experiments with the laser give scientists a clue about how matter behaves in these extreme conditions. Scientists at this laser facility are quick to point out that, for a fraction of a second, it produces "the brightest light in the universe." The power output of the laser briefly eclipses that of the brightest known natural phenomena, gamma ray bursts, by a factor of more than 100. Of course, the total power output of a gamma ray burst is much larger than that of the world's most powerful laser, because a gamma ray burst can be millions of miles long and thousands of miles wide, but on a per-volume basis, the laser wins.
The target of the laser is usually a few small gas clouds in a chamber, which get heated to millions of degrees Celsius and pressurized to a billion times more than pressure at sea level on Earth. In such conditions, matter is so compressed and energized that little real complexity or order can exist -- just atoms packed as closely together as is physically possible. The energy at the world's most powerful laser is so intense that it can cross the threshold necessary for the spontaneous production of antimatter. Antimatter, the reflection of conventional matter, spontaneously gets converted to energy upon contact with normal matter in a process known as annihilation. Annihilation can be observed in the test chambers only due to the unique particles released by the process.