ABSTRACT
Short pulse CO2 oscillator-amplifiers at 10 μm wavelengths are being developed to study the interaction of intense light beams with plasma at high density in order to confirm or deny theoretical concepts for laser-pellet fusion. Of the three laser systems which can reach the required energies and power levels (Nd: glass, atomic iodine and CO2) only the electrically excited CO2 laser shows promise of achieving the overall efficiency required for power production.
The subject of short-pulse (⩽ 2 ns) CO2 lasers is introduced by a discussion of CO2 laser kinetics as it applies to amplifiers and is followed by a review of the various techniques which have been developed for generating and detecting nanosecond and shorter pulses. Experimental results on the propagation and amplification of single line and multiband oscillator pulses are compared with theory. Following this general introduction the design of 1012 W CO2 laser systems and system components is discussed. The characteristics of electron-beam-controlled power amplifiers are summarized and a comparison is made between cold-cathode and hot-cathode electron guns. Finally, outstanding problems relating to systems performance, including pulse power conditioning, optical isolation and optical component design, fabrication and damage threshold are reviewed.
