Time-Domain Characterization of High-Speed Photodetectors

We measure the impulse response of single ultrafast photodetectors with a nominal bandwidth of 100 GHz including a full uncertainty analysis. 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 response above the single-mode cut-off frequency of the coaxial connectors. We show that such measurements up to a frequency of at least twice the nominal bandwidth are essential if the time-domain response of the photodetector has to be specified.