Bragg Grating Enhanced Polarization Instabilities

Experiments demonstrate a dramatic decrease in the polarization instability threshold as an optical pulse is tuned near the short wavelength edge of the photonic bandgap formed by a fiber Bragg grating. These enhanced nonlinear interactions and birefringent effects are modeled using coupled mode numerical simulations. Nonlinearities are shown to increase much more rapidly than the effective birefringence as the pulse wavelength approaches the bandgap edge.