Waveform Standards for Electrooptics: A Pulse Duration Comparison (Short Paper)

A transfer standard has been developed for use in comparing the measurement capability of the Automatic Pulse Measurement System (APMS) at the National Bureau of Standards to that of the recently developed electrooptic samplers. This transfer standard is a comb generator driven by a 90-MHz sine wave. Using this standard, measurements were made of the pulse waveform of a comb generator output with both the APMS and an electrooptic sampler. A comparison was then made of the pulse duration (full width at half maximum) obtained in the two waveform measurements. The result was a duration of 102 ps as measured by the APMS and 112 ps as measured by the electrooptic sampler. The signal-to-noise ratio at the comb generator input was improved over that of previous measurements, and a correction for pulse broadening was made to achieve this result. The pulse broadening was caused by the impedance mismatch between the sampler and the transmission system (50 Omega).