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 po wer sensor or an amplified receiver with an RF power sensor. It is cal ibrated with an expanded uncertainty of 0.06 dB (coverage factor = 2) using a heterodyne technique at 1.319 mu m We present a theory which a llows use of the transfer standard with arbitrary source modulation de pth. The calibration is transferred to a SDH/SONET test equipment manu facturer giving a final uncertainty well below the 0.3 dB uncertainty specified by ITU-TS (formerly CCITT) recommendation G.957. The transfe r standard may have other applications including calibration of CATV t est equipment, lightwave component analyzers, and lightwave spectrum a nalyzers.