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arXiv · 1612.02956

Observation of Two-photon Photoemission from Cesium Telluride Photocathodes Excited by a Near-infrared Laser

H. Panuganti·P. Piot
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Abstract

We explore nonlinear photoemission in cesium telluride (Cs$_2$Te) photocathodes where an ultrashort ($\sim 100$ fs full width at half max) 800-nm infrared laser is used as the drive-laser in lieu of the typical $\sim 266$-nm ultraviolet laser. An important figure of merit for photocathodes, the quantum efficiency, we define here for nonlinear photoemission processes in order to compare with linear photoemission. The charge against drive-laser (infrared) energy is studied for different laser energy and intensity values and cross-compared with previously performed similar studies on copper [P. Musumeci et al., \emph{Phys. Rev. Lett.}, \textbf{104}, 084801 (2010)], a metallic photocathode. We particularly observe two-photon photoemission in Cs$_2$Te using the infrared laser in contrast to the anticipated three-photon process as observed for metallic photocathodes.

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H. Panuganti, P. Piot. 2016-12-09. Observation of Two-photon Photoemission from Cesium Telluride Photocathodes Excited by a Near-infrared Laser. https://doi.org/10.1063/1.4977884

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