Electron-beam-pumped recombination lasers
The first known instance of electron-beam pumping of the 546.1 nm mercury laser is reported. This has been achieved using high-energy electrons to create intense ionization in a coaxial diode chamber containing a mixture of noble gases with a small amount of mercury vapor. Also reported are the results of a study of the 585.3 nm neon laser in He:Ne:Ar mixtures under similar experimental conditions. Both of these lasers are believed to be predominantly pumped by recombination. For the mercury laser, kinetic processes in the partially ionized plasma following the excitation pulse of high-energy electrons should favor the production of atomic mercury ions and molecular ions containing mercury. Subsequent recombination with electrons heavily favors the production of the 7$\sp3$S and 6$\sp3$D states of Hg, of which 7$\sp3$S is the upper level of the reported laser. For the neon laser, the dominant recombining ion has been previously shown to be Ne$\sb2\sp{+}.$ One of the dominant roles of helium in recombination lasers is inferred from the data for the neon laser at low helium concentrations. Helium appears to be necessary for the rapid relaxation of the electron energy which then increases the reaction rates for all known recombination processes thus increasing the pump rate into the upper state.
Engineering, Electronics and Electrical, Physics, General
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign