Accession Number : ADA190204

Title :   Short Wavelength Lasers Based on Selective Auger Processes and Core-Excited Metastable Levels.

Descriptive Note : Final technical rept. 19 Sep 86-19 Mar 87,

Corporate Author : STANFORD UNIV CA EDWARD L GINZTON LAB OF PHYSICS

Personal Author(s) : Harris, S E ; Young, J F

PDF Url : ADA190204

Report Date : Oct 1986

Pagination or Media Count : 47

Abstract : The goal of this program is to investigate, both theoretically and experimentally, new approaches to constructing XUV and soft x-ray lasers. At these short wavelengths, atomic spontaneous emission times are typically less than a nanosecond and, for levels that autoionize, are often less than a few picoseconds. It is technically very difficult to excite such levels directly to produce laser action in the way that is commonly done for visible laser levels. Practical short wavelength lasers will have a significant impact in many areas of critical national interest; applications include spectroscopy of surfaces, high resolution lithography, microscopy, and holography. The realization of the great promise of such applications, however, depends on the properties and practicality of the lasers developed. Although there is a 20 year history of proposals for XUV and soft x-ray lasers, most approaches require very high pumping powers. We have developed systems which can produce useful gain using only moderate input energies by combining the unique properties of particular atomic states with innovative experimental techniques. To date, we have observed gain in two species: Xe at 108.9nm, and Zn at three lines around 133nm. We have shown that useful gains, exp(3.6), can be achieved with input energies of less than 1J, and we have achieved small signal gains exceeding exp(40) using less than 4J input. In the latter case, an output energy of 20 micro J in a beam with 10 mrad divergence was measured at 108.9nm.

Descriptors :   *ATOMIC ENERGY LEVELS, *LASERS, *SHORT WAVELENGTHS, ENERGY, EXPERIMENTAL DESIGN, HIGH POWER, HIGH RESOLUTION, HISTORY, HOLOGRAPHY, INPUT, LITHOGRAPHY, METHODOLOGY, MICROSCOPY, OUTPUT, PUMPING, SIGNALS, SOFT X RAYS, SPECTROSCOPY, SURFACES, VISIBLE SPECTRA

Subject Categories : Lasers and Masers
      Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE