Nonlinear frequency conversion in a birefringent microstructured fiber tuned by externally applied hydrostatic pressure.
We studied vector frequency conversion in externally tuned microstructured fibers for applications as a novel, nonlinear fiber-optic sensor. We investigated both experimentally and numerically a possibility of shifting vector and scalar modulation instability gain bands by pressure-induced changes in the linear properties of a microstructured fiber. Our results show that polarization-dependent vector nonlinear processes sensitive to variation of fiber group velocity difference (group birefringence) exhibit a clear advantage for pressure-sensing applications compared with scalar nonlinear processes only sensitive to group velocity dispersion changes. Analytical predictions and numerical simu…
Nonlinear mode coupling in a birefringent microstructured fiber tuned by externally applied hydrostatic pressure
We studied the effect of power coupling between two linearly polarized modes, which occurs during nonlinear propagation in an externally tuned birefringent microstructured fiber. We investigated both experimentally and numerically the possibility of measuring hydrostatic pressure by tracking the nonlinear power coupling between the fiber polarization modes. We analyzed the impact of the fiber length exposed to pressure and the input polarization state on the coupling efficiency. We also revealed that the observation of nonlinear power coupling between the polarization modes is limited by linear coupling occurring in the leadthroughs to the pressure chamber. Moreover, we demonstrated that th…