Abstract: Techniques and devices for emulating polarization-mode dispersion in an optical signal that transmits through an optical fiber by using multiple birefringent wave-guiding sections that are interconnected to have adjustable polarization-changing connectors. The polarization of light transmitting from one section to another adjacent section can be modified differently between different adjacent sections according to a distribution function to produce one PMD state to represent one possible PMD state of a real PMD fiber. The connectors can be adjusted to produce different sets of polarization modifications to produce different PMD states to represent different possible PMD states of the real PMD fiber.