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Group index and time delay measurements of a standard reference fiber



B. L. Danielson, C. D. Whittenberg


We describe measurement techniques for establishing a standard reference fiber with well characterized group index and time of group delay. Evaluation of an interferometric method indicates that fiber group index can be determined with a total estimated uncertainty of about 0.03 percent in small samples. Group delay of the reference fiber was measured with an overall uncertainty less than 0.004 percent in a 7 km waveguide. We discuss the application of a standard reference fiber to calibration of the distance measurement accuracy of an optical time-domain reflectometer (OTDR).
NIST Interagency/Internal Report (NISTIR) - 88-3091
Report Number


Danielson, B. and Whittenberg, C. (1988), Group index and time delay measurements of a standard reference fiber, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 17, 2024)


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Created July 1, 1988, Updated November 10, 2018