Charles H. Skinner

Review of soft x‐ray lasers and their applications

The emerging technology of soft x‐ray lasers is in a transition phase between the first laboratory demonstrations of gain and the acceptance of soft x‐ray lasers as practical tools for novel applications. Current research is focused on several fronts. The operational wavelength range has been extended to the ‘‘water window,’’ important for applications in the life sciences. Gain has also been generated with substantially simpler technology (such as a 6 J laser) and this augurs well for the commercial availability in the near future of soft x‐ray lasers for a variety of applications. Advanced soft x‐ray laser concepts are being developed from investigations into ultrahigh intensity laser/matter interactions. The first applications of soft x‐ray lasers to x‐ray microscopy and holography have begun. In this paper a brief historical perspective of x‐ray laser development will be followed by a review of recent advances in recombination, collisional, and photopumped systems and applications. A summary of curren...

High-sensitivity stimulated-emission detector for soft-x-ray laser research

A novel, extremely sensitive system for the detection of stimulated emission is proposed. The principle of the detection method relies on the major difference between stimulated and spontaneous emission, its directionality. A unique feature of the system is the use of a separate spontaneous-emission source. The system is predicted to be sensitive to gain-length products down to 0.1 and below, a capability that would be useful in media in which stimulated emission is weak compared with spontaneous emission. This will have important applications to the development of soft-x-ray lasing in novel systems.

Small-scale soft x-ray laser development at Princeton

A program aimed at the development of a table-top soft X-ray laser on the CVI 18.22 nm transition is reported. A gain-length product of GL = 2.5-3.5 has been observed for a variety of target geometries using a 3-ns 6-15 J Nd:glass driving laser emitting at 1.05 micron. Plans for future experiments are outlined.

Applications of soft x-ray lasers

The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x- ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

Toward small-scale x-ray lasers (Invited Paper)

An overview of the X-ray Laser project at Princeton University will be given. Emphasis will be on improvements being made to the small scale soft x-ray laser (SXL). New target designs to enhance cooling and others to reduce losses due to beam refraction have been introduced though results are stilt preliminary. Proof of principle experiments for the application of the SXL to both transmission and reflection microscopy have been performed. To generate shorter wavelength x-ray lasers on a reasonable scale-size, a high power, 300 fsec pulse duration, ultraviolet KrF laser system (the PSP-laser) has been developed. Of the several theoretical schemes which exist, the two-laser approach and a newly proposed recombination approach will be described. The new approach proposes to scale the existing 18.2 nm recombination x-ray laser to shorter wavelength (<4 nm) by making use of the short-pulse pump laser and rapid cooling associated with the adiabatic expansion of µsphere targets.

Novel target manipulation system for x-ray laser studies

In the 1980s many exciting advances in the field of soft x-ray lasers took place. A novel experimental set-up was developed at Princeton to improve the performance and extend the wavelength range of existing soft x-ray lasers. In th1s paper a new target manipulation system capable of remotely aligning multiple targets in a vacuum chamber within a magnetic field is described Alignment to the magnetic field orientation, incident pump laser and the two axial diagnostics: a high resolution spectrometer equipped with a multichannel array and a time resolved imaging spectrometer is presented. We include a brief explanation of the Macintosh- Camac based data acquisition system. In addition we discuss the possibifity to increase in the near future the brightness of the x-ray laser beam by several orders of magnitude by developing a cavity with multilayer mirrors.