it has been extremely difficult to characterize the SONET/SDH standard
receiver with tolerances of +/- 0.3 dB. This paper describes a method
for calibrating photoreceiver frequency response with the low inheren
t uncertainty of the U.S. National Institute of Standards and Technolo
gy Nd:YAG heterodyne system and transferring this calibration to a pro
duction test system while maintaining a low uncertainty.