Visible CW and Long-Pulse Lasing in S II and S III.
Abstract
The sulfur ion laser was investigated in three slotted-hollow cathode and two flowing positive column laser (PCL) configurations. Laser action was achieved only in the PCL configurations. In the 1.76-mm diameter x 500-mm long laser, true CW operation was achieved on 9 green transitions in S II. Quasi-CW operation in the PCL at 4-ms pulse lengths occurred on 15 S II and 2 S III transitions covering the range from 4925- to 5819-A. A new laser transition at 5011.6A in S II was discovered. Spontaneous and TEM00 laser intensity vs. discharge current up to 17 amps were measured. Small signal gains were 40% to 60% per meter for the stronger lines. Optimum output mirror transmission was about 7% producing 250-mw TEM00 and 500-mw multimode multiline power. Optimum operation was at 0.6 torr Ne buffer gas flowing over sulfur crystals at 116C at 0.25 torr cc/sec. The excitation mechanism for the laser transitions is definitely by electron impact. Approximate calculations suggest that the electron temperature may be 5- to 10-eV and the order-of-magnitude cross section for direct electron excitation of the 5454-A upper level from the ground state of neutral S is 10 to the minus 17 power to 10 to the minus 16 power -cm2.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1974
- Accession Number
- ADA017217
Entities
People
- Robert A. Dessert
Organizations
- Air Force Institute of Technology