Abstract: A device for performing polarization mode dispersion (PMD) measurements of an optical fiber is disclosed. The PMD measurement device employs a fixed analyzer method, and includes a tunable Fabry-Perot inferometer as the wavelength-selective element and an optical bandpass filter for spectrum calibration. A novel scanning algorithm, which performs multiple scans at different velocities, enables accurate PMD measurements, even of moving optical cable. The tunable Fabry-Perot interferometer is able to scan over a wide wavelength range and yet have a narrow linewidth, such that a wide range of PMD values can be measured.

Abstract: An optical time domain reflectometer (OTDR) operates in a gated mode, enabling a predetermined width of an optical fiber to be analyzed. The OTDR may test only a desired position on the fiber. Data obtained along different lengths of the fiber may be combined together, providing a thorough representation of the fiber characteristics. Alternatively, specific regions of the fiber may be analyzed. The OTDR measures the backscattered signal using photon-counting techniques, and improves the accuracy of such algorithms by attenuating the incoming backscattering signals automatically and independently at each position in the fiber being tested. The OTDR simultaneously achieves a high dynamic range and a high temporal/spatial resolution, an improvement over conventional OTDRs.