scope:

Intent

This Standard specifies a procedure for the measurement of the return loss of a fiber optic interconnection on single mode, highly linearly birefringent optical fiber, i.e. either polarization-maintaining (PM) fiber or polarizing (PZ) fiber. The connector can be mounted on the PMF/PZF pigtail of a component or part of a cable assembly. Return loss, as used in this Standard, is the ratio of power incident on, or entering the DUT, to the total power reflected by the DUT, expressed in decibels. The method described in this Standard is the PMF/PZF equivalent of ANSI/TIA/EIA-455-107 with the return loss reported as a positive number.

Alternately, this measurement is sometimes called "reflectance" for which the values are simply the negative of return loss. Thus, "reflectance" is the ratio in decibels of the power reflected by the DUT, to the power incident on, or entering the DUT. The preferred terminology is "return loss" as will be used throughout the rest of this Standard.