Obituary of Herman Z. Cummins
NOV 18, 2010
DOI: 10.1063/PT.4.1913
Herman Cummins and I were the Townes graduate students assigned to make the first IR continuous-wave potassium vapor laser and, later, the cesium vapor laser outlined in the 1958 paper Charles Townes wrote with Arthur Schawlow.
We began in 1958, but we had difficulty pumping potassium with a high-pressure mercury lamp at 404.7 nm, so we turned to cesium vapor pumped with a helium discharge tube at 388.8 nm. We used an elliptical reflecting cylinder and tried sapphire tubing and sapphire windows to avoid cesium darkening in glass.
By June 1960 we had measured gain but no laser oscillation. However, the cesium laser never did work at Columbia.
© 2010 American Institute of Physics
