X-ray laser

The plasma x-ray lasers rely on stimulated emission to generate or amplify coherent, directional, high-brightness electromagnetic radiation in the near X-ray or extreme ultraviolet region of the spectrum, that is, usually from ~3 nanometers to several tens of nanometers (nm) wavelength.

Because of high gain in the lasing medium and short upper-state lifetimes (1–100 ps), X-ray lasers usually operate without mirrors; the beam of X-rays is generated by a single pass through the gain medium.

The emitted radiation, based on amplified spontaneous emission, has relatively low spatial coherence.

[1] The most often used media include highly ionized plasmas, created in a capillary discharge or when a linearly focused optical pulse hits a solid target.

Common methods for creating plasma X-ray lasers include: An alternative amplifying medium is the relativistic electron beam in a free-electron laser, which, strictly speaking, uses stimulated Compton scattering instead of stimulated emission.