Narrow-band measurement of differential group delay by a six-state RF phase-shift technique: 40 fs single-measurement uncertainty

Published

February 1, 2004

Author(s)

Paul A. Williams, Jonathan D. Kofler

Abstract

We describe in detail our implementation of a modulation phase shift (MPS) technique for narrow-bandwidth measurement of differential group delay (DGD) and the principal states of polarization (PSP) in optical fibers and components. Out MPS technique involves launching six orthogonal polarization states (as opposed to the four states typically launched) to achieve improved measurement stability. The measurement bandwidth is 4.92 GHz (twice the 2.46 GHz RF modulation frequency), the measurement time is 13 s per point, and the single-measurement uncertainty is better than 40 fs (~95% confidence interval) for DGD values from 10 to 1000 fs. We demonstrate that this uncertainty (95% confidence interval) on a device with 315 fs of DGD. Sources of uncertainty are detailed, including a DGD contribution from the detector itself. Simulations illustrate the uncertainty contribution of multiple DGD elements in series.

Citation

Journal of Lightwave Technology

Volume

22

Issue

2

Pub Type

Journals

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Keywords

DGD, MPS, PMD, Polarization-Mode Dispersion, Principal State of Polarization, PSD, PSP, RF Phase Shift

Citation

Williams, P. and Kofler, J. (2004), Narrow-band measurement of differential group delay by a six-state RF phase-shift technique: 40 fs single-measurement uncertainty, Journal of Lightwave Technology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=31437 (Accessed October 20, 2025)