Visible to ultraviolet femtosecond autocorrelation measurements based on two-photon absorption using ZnSSe photodetector

We demonstrated for the first time an autocorrelator based on two-photon ab sorption of ZnSSe photodetectors which is capable of measuring femtosecond laser pulses from 800 to 400 nm. This antocorrelator has a very broad bandw idth, high sensitivity and is capable of measuring laser pulses with high r epetition rate. These results could lead to cost effective ultrafast autoco rrelators with a single detector head to cover the whole of visible to near UV spectral region. Using a ZnMgS photodetector with a larger bandgap enab les the autocorrelator to be more sensitive at 400 nm and extends the respo nsivity further into the ultraviolet wavelength of 350 nm. (C) 2001 Elsevie r Science B.V. All rights reserved.