Visible CW and Long-Pulse Lasing in S II and S III.
Final rept. Aug 71-Nov 74,
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING
Pagination or Media Count:
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 ccsec. 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.
- Lasers and Masers
- Atomic and Molecular Physics and Spectroscopy