Picosecond optical autocorrelation measurements on single optoelectronic devices

We report a simple optical correlation technique for measuring the intrinsic response speeds of photosensitive electronic devices. The method requires neither high-speed electrical connections to a device nor cross-correlation measurements between two devices, but relies instead upon measuring the nonlinear component of the response of a single device to two correlated optical pulse trains. Measurements upon high-speed GaAs photodiodes are reported. A detector was found to be sufficiently fast to be capable of replacing second harmonic generation techniques for monitoring the mode-locking quality and the duration of a beam of 1.5 ps pulses. An optical pulse is found to enhance the sensitivity of another device to a subsequent pulse.