PICOSECOND OPTICAL MIXING IN FAST PHOTODETECTORS

We report a simple optical correlation technique which is capable of measuring the intrinsic response speeds of fast photosensitive electronic devices. The appeal of the method is that neither high-speed electrical connections to a device nor cross-correlation measurements between two devices are required. An example is given of measurements of the response speed of a GaAs Schottky barrier photodiode. Under appropriate illumination conditions the detector is found to be sufficiently fast to be capable of replacing optical second harmonic generation techniques for monitoring the quality of a beam of 1. 5 ps pulses.