Exploration of applying Cesium-Xenon system as a sensitive broadband frequency up-conversion photodetecting medium

Alkali metal vapor was applied as sensitive frequency-conversion photodetectors, however, their application was limited by their natural narrow (similar to 100 MHz) sensing frequency range. Here, Cs-Xe excimer is used to break this limitation. Demonstration of Cs-Xe frequency up-conversion photodetector is given. Using excimer transition, 550-552 nm light is converted to 541 nm fluorescence, this conversion wavelength band is much larger than a typical atom energy level transition. The frequency up-conversion background is mainly energy pooling fluorescence, which varies with Cs 6P(3/2) state number density on roughly a cubic function. Atom collision generated Cs 12D(J), 9F(J) levels are measured and discussed. By switching excimer transitions selected, e.g. using Cs nP(J) (n = 7, 8, & mldr;) related upward excimer transitions, it is possible to detect light with other wavelength from infrared to terahertz band. The concept in this work may get application in photon detection with high sensitivity.