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 absorption of ZnSSe photodetectors which is capable of measuring femtosecond laser pulses from 800 to 400 nm. This antocorrelator has a very broad bandwidth, high sensitivity and is capable of measuring laser pulses with high repetition rate. These results could lead to cost effective ultrafast autocorrelators with a single detector head to cover the whole of visible to near UV spectral region. Using a ZnMgS photodetector with a larger bandgap enables the autocorrelator to be more sensitive at 400 nm and extends the responsivity further into the ultraviolet wavelength of 350 nm. (C) 2001 Elsevier Science B.V. All rights reserved.