Soft X-Ray Lasing in an Al Plasma Produced by a 6 J Laser

For the first time, amplified spontaneous emission of Al ions was observed in a recombining plasma produced by a low-power driving laser of only 6 joules. It had a high gain of 3.4 cm-1 for a soft X-ray wavelength of 105.7 Å of Al XI. This lasing was achieved by tightly focusing a pumping glass laser to a line 40 µm wide and 12 mm long onto a slab target. This result can pave the way to a low-power-pumped X-ray laser.