 Another samarium @-@ based laser became the first saturated X @-@ ray laser operating at wavelengths shorter than 10 nanometers . It provided 50 @-@ <unk> pulses at 7 @.@ 3 and 6 @.@ 8 nm suitable for applications in holography , high @-@ resolution microscopy of biological specimens , <unk> , interferometry , and radiography of dense plasmas related to confinement fusion and astrophysics . Saturated operation meant that the maximum possible power was extracted from the lasing medium , resulting in the high peak energy of 0 @.@ 3 <unk> . The active medium was samarium plasma produced by irradiating samarium @-@ coated glass with a pulsed infrared Nd @-@ glass laser ( wavelength ~ 1 @.@ 05 µm ) . 
