Electron trapping materials for use in a picosecond infrared streak camera

We describe our research on the employment of an infrared upconversion scre en made of electron trapping material (ETM) in combination with the high se nsitivity of the S-20 photocathode responsive to visible radiation to produ ce a streak camera arrangement capable of viewing and recording infrared in cident pulses. The ETM-based upconversion screen converts 800-1600 nm infra red radiation to visible light which is viewed or recorded by the S-20 phot ocathode. The peak values of the upconversion efficiency are located at 116 5 nm for CaS:Eu, Sm and 1060 nm for CaS:Ce, Sm. The present experiment show ed time resolution was 12.3 ps for a CaS:Eu, Sm screen and 8.4 ps for a CaS :Ce, Sm screen. The minimum detectability is 4.8 x 10(-9) J/mm(2) (minimum detectability of the coupled visible streak camera is 8.3x10(-10) J/mm(2)). Other parameters, such as spatial resolution and dynamic range, have also been measured and analyzed. The results show ETM can be used in the measure ment of infrared ultrafast phenomena up to picosecond time domain. In consi deration of the limited number of trapped electrons in ETM, the infrared-se nsitive streak camera consisting of an ETM-based upconversion screen is sui table to operate in the single shot mode. (C) 1999 American Institute of Ph ysics. [S0034-6748(99)00112-4].