” Sometimes a laser’s quality and usefulness is measured in pure watts. In that respect, a new laser in production at Lawrence Livermore National Laboratories (LLNL) can certainly hold its own: at a full petawatt, otherwise known as one quadrillion watts, it’s powerful enough to drive the world’s most demanding experiments.
Sometimes, though, you need a laser to be able to produce incredibly short bursts of light, and here it shines as well: each pulse from the laser lasts just 30 femtoseconds. At 10 Hz, it can fire these quadrillion watt bursts of light faster than an AK47.”
” The High Repetition Rate Advanced Petawatt Laser System (HAPLS) will be a major step forward for high-energy laser science, primarily because of that firing rate. A petawatt laser is not unheard of, since a watt is a measure of power over time — joules per second, to be precise. Thus, delivering more than 600 joules over a 450 femtoseconds (as LLNL’s previous petawatt laser can) is not all that different from delivering 30 joules over 30 femtoseconds. They’re both around a petawatt. However, with a firing rate of 10 per second, the overall output can be hundreds of times greater over longer periods (like a long, sluggish microsecond).”