An automated autocorrelator for the measurement of high-frequency femtosecond pulses

An automated autocorrelator based on a first-order auto-correlation function has been designed and assembled for measuring femtosecond pulses from lasers operating at a high-frequency repetition rate. In particular, it has been used to characterize the laser oscillator Time-Bandwidth GLX 200. The autocorrelator scheme is based on a Michelson interferometer; the linear displacement of the movable mirror, signals from the photodiode (IRPD) (autocorrelation function), pulse duration calculation and statistics were controlled and recorded by an I/O digital card and a dedicated Labview program. Our results can effectively reproduce the reference data provided by the manufacturer. The system can be successfully applied to low-energy pulses since the operating threshold energy relies on IRPD sensitivity only.