Laser sources combining techniques

Lasers are extremely intense sources of light power, commonly used to deposit energy at a distance, whether to measure physical parameters such as distance, the speed of an object or the concentration of a molecule, or to interact with a material to modify its physical state by melting or burning it (e.g. laser cutting of metal parts in the automotive industry). Some military applications, such as laser weapons, use a laser beam to heat up a target from a distance, with the aim of damaging or even destroying it. Whatever the application, the laser's range of action, speed of interaction or sensitivity and accuracy for measurement applications can be improved by using more powerful lasers. This is why we often seek to increase the power emitted by laser sources.

The most powerful, compact and efficient lasers today are solid-state lasers, so called because the medium generating the light power is in solid form: usually a cylindrical rod or parallelepiped plate. Doped optical fibers are also the solid media of choice for compact, robust and efficient laser sources. However, these solid media heat up when used, and their performance degrades if the heating becomes too great, limiting their power rise. In fiber lasers, where these thermal effects are much less limiting than in solid-state bar or plate lasers, non-linear effects also limit power ramp-up.

A glossary of terms is provided at the end of the article.