A transfer standard for measuring photoreceiver frequency response

We have developed a photoreceiver frequency response transfer standard which can be used to measure the optical modulation transfer function of a modulated optical source. It combines a photodiode with an RF power sensor or an amplified receiver with an RF power sensor. It is calibrated with an expanded uncertainty of 0.06 dB (coverage factor=2) using a heterodyne technique at 1.319 /spl mu/m. We present a theory which allows use of the transfer standard with arbitrary source modulation depth. The calibration is transferred to a SDH/SONET test equipment manufacturer giving a final uncertainty well below the 0.3 dB uncertainty specified by ITU-TS (formerly CCITT) recommendation G.957. The transfer standard may have other applications including calibration of CATV test equipment, light-wave component analyzers, and light-wave spectrum analyzers.