Measuring the frequency response of gigabit chip photodiodes

We describe a calibration and measurement procedure for determining the int rinsic frequency response of gigabit chip photodiodes embedded in simple te st fixtures. The procedure is unique because we make the measurements in th e time domain using a calibrated oscilloscope, and we then apply frequency- domain mismatch corrections to remove the effects of the fixture, bias T, a nd cables from the measurements. We demonstrate the procedure on photodiode s with an active region of approximately 150-mum diameter excited by short 800-nm wavelength optical pulses.