Return Loss Measurement in the Presence of Variable Insertion Loss Using Optical Frequency Domain Reflectometry
The capability of measuring localized insertion loss using OFDR presents a unique opportunity to provide consistent
measurements of device RL even in the presence of variable connector loss, even for short lead lengths. This paper outlines the methodology used to establish a value for the scatter in optical fiber, and how this Rayleigh scatter level is used to maintain consistent reflection measurements.
The high spatial resolution and high sensitivity inherent to optical frequency domain reflectometery enables precise measurements of distributed insertion loss and return loss events. The ability to compensate return loss for variable insertion loss greatly adds to the accuracy and practicality of measurements. Further, the capability of measuring the Rayleigh backscatter internal to the instrument provides a stable power calibration artifact.
S. Kreger et al., “Return Loss Measurement in the Presence of Variable Insertion Loss Using Optical Frequency Domain Reflectometry,” NIST SPECIAL PUBLICATION SP, 2006, 1055, 18.