Fifty years after the first beam of coherent light shone out of a ruby crystal, lasers have expanded in every direction, ranging from as big as three football fields to as small as a few layers of atoms, producing wavelengths from deep in the X-ray regime to far into the infrared. Engineers are pushing the technology ever further, and here are some of the records they have set.
The laser with the highest peak power in the world—1.1 petawatts, about 2200 times the power output of the entire U.S. electrical grid—is run by the University of Texas at Austin. The laser starts with a short, low-energy laser pulse and stretches it to 10 000 times its length, amplifies it to 186 joules, then recompresses it to 167 femtoseconds. The laser provides scientists with enough power to study thermonuclear fusion as well as to examine the nature of plasmas and the properties of dense matter in brown dwarf stars.