How do spectral lasers work?

Laser-induced plasma spectroscopy, or LIBS, has made significant progress in the past 10 years. Solids, liquids and gases can be analyzed and results can be obtained quickly with little damage to the sample. Not only that, but the method can also be used outside the lab, unlike analytical tools that require samples to be taken in the lab. For example, LIBS are used to detect surface contamination at certain nuclear reactors around the world. The laser system is only a few feet from the surface of the reactor and can still operate efficiently. The system keeps most of the instrument inside a radiation shield, and lasers pass through a lens that concentrates energy in the sample. Some systems work in the laboratory and contain small samples placed in chambers, perhaps only a few inches thick. Others can be taken to distant places and used to analyze larger objects. Either way, the closer you are to the center of the laser, the less energy it takes to decompose the sample. In fact, LIBS laser pulses typically have only 10 to 100 millijoules of power. To put this number in context, remember that joules are the amount of energy needed to lift an apple three feet high. One millijoule is 0.001 joule, which is much less energy. But only surface wear particles. As the particles are removed from the surface of the sample, they ionize and form small clouds of plasma -- a chemical called "laser ignition."