2ps electric pulse measurement using scanning tunneling/force optoelectronic microscope

We have developed new measurement systems for ultrafast electric signals using a STM (scanning tunneling microscope) and a SFM (scanning force microscope). A photo-conductive semiconductor switch (PCSS) on the probe is used as a sampler in an optical sampling procedure. We measured electric pulse with 2.5 ps width that corresponds to a time resolution better than 2 ps. This substantial improvement was realized by using low temperature grown GaAs for the PCSS and by decreasing the probe dimension.