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We report the demonstration of soft x-ray microscopes with resolution down to sub-38 nm using tabletop soft x-ray laser illumination. One of the compact microscopes combines the 46.9 nm wavelength output from a capillary discharge Ne-like Ar laser with a reflective condenser and a free standing zone plate objective. High quality images were acquired with this microscope in transmission mode and reflection mode. The latter includes images of an integrated circuit pattern containing polysilicon features on silicon. The spatial resolution for this microscope is between 120-150 nm. Increased resolution was demonstrated in another microscope using 13.2/13.9 nm wavelength illumination from Ni-like Cd/Ag transient soft x-ray lasers in combination with diffractive zone plate optics for both the condenser and objective. Using an objective zone plate with a 50 nm outer zone width, this optical system achieved a record sub-38 nm spatial resolution. These results demonstrate the feasibility of using compact high repetition rate soft-x-ray laser sources in nanometer-scale microscopy. [ABSTRACT FROM AUTHOR]

We have demonstrated saturated tabletop lasers operating at 5 Hz repetition rate with microwatt average powers at wavelengths between 18.9 nm and 13.2 nm in the 4d 1P1-4p 1S0 transitions of Ni-like ions. Lasing was also observed on transitions of the same isolectronic sequence for wavelengths as low as 10.9 nm in Ni-like Te, and on transitions near 30 nm in Ne-like ions. The results were obtained using picosecond laser heating pulses with an energy of only 1J by optimizing the grazing incidence angle of the pump beam for maximum energy deposition. As a further step in the development of these lasers we also realized the first demonstration of saturated amplification of a high harmonic seed in a transient collisional soft x-ray laser amplifier created by heating a solid target. A 32.6 nm Ne-like Ti amplifier was used to amplify a seed pulse from the 25th harmonic of Ti:Sa into the gain saturation regime. The amplified beam was measured to approach full spatial coherence. The peak spectral brightness is estimated to be ~ 2x1026 photons/(s.mm2.mrad2 0.01% bandwidth). The scheme is scalable to produce extremely bright lasers at very short wavelength. [ABSTRACT FROM AUTHOR]