Glossary
Fiberoptic measurements

Dispersion chromatique; Chromatic Dispersion

Time spread of pulses as they propagate through an optical fiber, due to the wavelength dependence of the propagation time. Also known as the chromatic dispersion coefficient in ps.(km.nm)^–1.

DGD (Differential Group Delay)

Difference in propagation time between the two polarizations in a single-mode fiber. Measured in ps.km^–1.

DMD (Differential Mode Delay)

Difference in propagation time between the different propagation modes of a multimode fiber. Depending on specifications, this may be between extreme modes or between neighboring modes. Measured in ps.m^–1.

DSF (Dispersion Shifted Fiber)

A single-mode fiber whose zero-dispersion wavelength is shifted towards the 1,500 nm window, instead of towards 1,310 nm as in a standard fiber.

Gradient index; Graded-index

Multimode...