Mario C. Marconi

Toward saturation of a discharge-pumped soft x-ray amplifier

Operation of a discharge-pumped 46.9 nm Ne-like Ar amplifier at gain length products up to gl approximately equal to 14 is reported. The laser line intensity is observed to increase exponentially for plasma column lengths up to 15 cm, above which it is observed to saturate. The saturation behavior is discussed. Results of the parameterization of the discharge pumped amplifier and the measurement of the soft x-ray laser pulsewidth also are reported. The use of an axial magnetic field, that limits the maximum plasma compression and decreases the density gradients, is observed to cause a moderate increase of the soft x-ray laser intensity and a beam profile that is more Gaussian.

Image Plane Holographic Microscopy With a Table-Top Soft X-Ray Laser

We demonstrate image plane holographic microscopy in the soft X-ray (SXR) spectral region, combining the coherent output from a 46.9-nm wavelength table-top SXR laser and two Fresnel zone plates. Phase and amplitude maps of the object are simultaneously obtained from holograms created at the image plane by the superposition of a reference and object beam originating from the zero and first diffraction order of the zone plates. We have used the microscope to record holograms of nanometer-scale periodic Si elbow patterns with 30% absorption contrast at the laser wavelength. The measured phase shift of 2.3 rad accurately predicts the Si dense line step height of 100 nm. The scheme is scalable to shorter wavelengths and allows for simultaneous high spatial and temporal resolution.

Dense plasma diagnostics with an amplitude division soft X-ray laser interferometer based on diffraction gratings

We report the demonstration of an amplitude-division soft-x-ray interferometer that can be used to generate high-contrast interferograms at the wavelength of any of the saturated soft-x-ray lasers (5.6-46.9 nm) that are available at present. The interferometer, which utilizes grazing-incidence diffraction gratings as beam splitters in a modified Mach-Zehnder configuration, was used in combination with a tabletop 46.9-nm laser to probe a large-scale (~2.7-mm-long) laser-created plasma.

Interferometric lithography at 47 nm with a table-top laser

We use interferometric lithography to demonstrate printing of dense lines as thin as 30 nm on polymethyl-metacrylate using the high average power output from of a /spl lambda/ = 46.9 nm compact high repetition rate EUV laser.

70 nm lensless diffractive microscopy using tabletop soft x-ray sources

We use curvature correction and high-numerical-aperture imaging to demonstrate a soft-X-ray diffraction microscope with 70-90 nm resolution using two tabletop coherent sources. This near-diffraction-limited resolution of 1.5lambda is a first for X-ray diffractive imaging.

Picosecond x-ray laser interferometry for probing dense laser-produced plasmas

Summary form only given, as follows. We describe precision interferometric characterization experiments using the picosecond, 14.7 nm x-ray laser source generated on the Compact Multipulse Terawatt (COMET) laser facility together with the Mach-Zehnder type diffraction grating interferometer. A review of the results from dense, mm-scale line focus plasma experiments will be described with detailed comparisons to 1-, 1.5- and 2-D hydrodynamic simulations. Ongoing experiments on smaller spot focus high intensity plasmas will be discussed.

Spatially coherent tabletop soft X-ray laser sources with milliwatt average power

We summarize the development status of milliwatt average power tabletop soft X-ray lasers based on fast capillary discharges with essentially full spatial coherence, and give examples of their use in dense plasma interferometry, soft X-ray reflectometry, laser ablation, and plasma generation.

Progress in dense plasma interferometry with table-top soft X-ray laser

We report progress in soft X-ray interferometry of dense plasmas using a very compact 46.9 nm discharge-pumped laser. Soft X-ray interferograms of /spl sim/300 /spl mu/m dimension plasmas generated by /spl sim/0.6 J pulses from a Nd:YAG laser focused into a <30 /spl mu/m diameter spot were recorded and analyzed. The spatial density distribution of the plasma was measured for densities up to /spl sim/6.5/spl times/10/sup 20/ cm/sup -3/.

Advances in compact discharge-pumped soft X-ray lasers and applications

Summary form only given. For many years researchers have envisioned the development of compact high repetition rate soft lasers with high spatial coherence that be routinely used in numerous applications. With demonstrated average powers of several mW and millijoule-level pulse energy at 46.9 nm the Ne-like Ar capillary discharge-pumped laser is the first compact laser to reach this goal. We summarize the development status of tabletop soft X-ray lasers based on capillary discharge excitation, and give examples of their successful use in dense plasma interferometry, soft X-ray reflectometry for the determination of optical constants, characterization of diffraction gratings, laser ablation of materials, and plasma generation. Lasing at 52.9 nm line in Ne-like Cl, and the prospects for lasing at shorter wavelengths are also discussed.

High resolution imaging of a dense plasma with a table-top soft X-ray laser

We report the results of the first plasma diagnostics experiment conducted utilizing a Y/sup +/ Ne-like table-top soft X-ray laser. The evolution of the plasma of a micro-capillary discharge was studied using a very compact 46.9 nm discharge pumped table-top soft X-ray laser as backlighter.