Real-time polarization mode dispersion monitoring system for a multiple-erbium-doped fiber amplifier, dense wavelength division multiplexing optical fiber transmission by amplified spontaneous emission modulation and acousto-optic tunable fiber scanning techniques.

Without interruption or affecting the transmission of ordinary payload channels, we propose a real time polarization mode dispersion (PMD) monitoring system for long-haul, multiple erbium-doped fiber amplifier (EDFA), dense wavelength division multiplexing (DWDM) optical fiber transmission using modulated amplified spontaneous emission (ASE) of one of the EDFAs as the supervisory (SV) signal source. An acousto-optic tunable filter (AOTF) at the receiver side is adopted to scan the spectrum of the transmitted ASE SV signal. Using the fixed-analyzer method, PMDs of different wavelength bands that range from 1545 to 1580 nm of a DWDM fiber-optic communication system can be found by adaptively changing the radio frequency of the AOTF.

Polarization-mode dispersion effect of an acousto-optic tunable filter.

The effect of the polarization-mode dispersion (PMD) of an acousto-optic tunable filter (AOTF) is studied both theoretically and experimentally. A coupled-mode method derived from Maxwell's equations is proposed to study the evolution of the polarization of light and hence the deterministic dynamics of the PMD inside an AOTF. It is found that the PMD value of a typical AOTF is around several picoseconds and is adjustable by tuning the strength of the applied sound signal.

Theoretical and experimental studies of polarization mode dispersion of an electro-optic Mach-Zehnder modulator.

A theoretical model is developed to study the polarization mode dispersion effect in an electro-optic Mach-Zehnder interferometric (MZI) modulator. The Stokes parameters and differential group delay (DGD) of the output light of a MZI modulator can be analytically derived with the proposed model, which is based on a three-dimensional Maxwell's wave equation approach. The theoretical model is validated to the extent possible by comparing the theoretical results of the Stokes parameters and DGD with experimental measurements that are based on the wavelength-scanning method and the Jones matrix eigenanalysis method.