SYSTEM AND METHOD FOR MEASURING POLARIZATION MODE DISPERSIONSUITABLE FOR A PRODUCTION ENVIRONMENT

摘要

A system for measuring polarization mode dispersion (PMD) in a fiber using a polarizer controlling the polarization state of light input to the fiber and a polarization analyzer measuring the polarization state of light output from the fiber. Jones matrix analysis is applied to data derived from three input polarization states and two wavelenghts of probing radiation. Performance is improved by using incoherent light sources such as light emitting diodes in conjunction with two bandpass filters. However, a laser source and optical detector are used to align the fiber. The system is particularly useful in measuring PMD values in short lengths of fiber and mapping those values with a long fiber from which the test fiber was cut. Preferably, the PMD is measure d for various values of twist experimentally induced in the test fiber, and th e short-length PMD value is that associated with zero-internal twist in the fiber as calculated according to a model. The fiber may also be loaded durin g measurement.