Improved Optoelectronic Technique for the Time-Domain Characterization of Sampling Oscilloscopes

We report on the enhancement of the Physikalisch-Technische Bundesanstalt´s (PTB´s) ultrafast optoelectronic measurement facility by characterizing the full impulse and step response of a 70-GHz sampling oscilloscope. A novel optoelectronic technique for the generation and the detection of ultrashort voltage pulses, which serve as calibration signals for the oscilloscope, is introduced. The uncertainty of the oscilloscope´s time-domain response is derived from a Monte Carlo analysis. Aside from a more complete characterization, our enhanced technique considerably reduces the uncertainty of rise-time measurements.