They are working on a plan to build a 75PW laser called the Optical Parametric Amplification Line (OPAL). Maximize laser power. The laser pointer, invented in the 1960s, uses an external “pump” such as a flash lamp to excite electrons in a laser material-usually a gas, crystal or semiconductor. When one of the excited electrons returns to its original state, it releases a photon.
This in turn stimulates another electron to release photons, and so on. Because power equals energy divided by time, there are two main ways to maximize power: either increase the laser’s energy or shorten the duration of the pulse. In the 1970s, researchers at Lawrence Livermore National Laboratory focused on ways to increase the power of lasers.
Their approach is to pass the beam through another laser crystal made of neodymium-doped glass. However, beams exceeding a certain intensity can damage the amplifier. To avoid this problem, LLNL had to make the amplifier bigger-up to tens of centimeters in diameter. But in 1983, he made a breakthrough in working at the Polytechnic in Paris, France. He realized that shorter laser pointers pulses could be extended in time by a diffraction grating, reducing their intensity.