Characterization of high-speed photodetectors using a laser-based vector network analyzer

We report the characterization of single and balanced ultrafast photodetectors. For this purpose we use a recently developed laser-based vector network analyzer, but no other measurement instrumentation. Our analysis includes full mismatch correction and takes into account the frequency-domain responses above the single-mode frequency of the coaxial connectors. We show that such measurements are essential if the time-domain response of the photodetectors has to be specified.