Sulfur discharges as high efficacy light sources

Summary form only given. It has been reported that a high-pressure, high-power-density sulfur discharge converted 50% of the applied microwave energy to visible light with a color rendering index of over 85. Recent advances in this technology are reviewed. Power densities in excess of 4000 watts/cc of bulb volume have been achieved, and coupled power levels up to 6000 watts of microwave power have been demonstrated. Efficacy has been investigated as a function of discharge size. A method for altering the angular distribution of the light intensity which involves reabsorption of "unwanted" light and the subsequent reradiation in a more favorable direction is examined. A model has been developed to explain the observations.