Modeling nonlinear high-pressure sensors based on degenerate four-wave mixing in photonic crystal fibers

We propose a high-pressure sensing mechanism in solid-core silica photonic crystal fibers (PCF) that is based on the nonlinear optical process of degenerate four-wave mixing. A quite simple configuration for the pressure sensor is given and is theoretically investigated by obtaining signal gain spectra. We focus on the Stokes and anti-Stokes sidebands that are generated during propagation of the field along the PCF due to the interplay of dispersion and nonlinear optical effects. We have considered wave propagation in the normal dispersion regime with the inclusion of negative fourth-order dispersion. We have also considered a pumping field with wavelength of 1076 nm and peak power of 3000 W that propagates along a PCF with 40 cm of length. We have optimized sensitivity, varying lattice pitch and air-hole diameter, and we have obtained high sensitivities of the Stokes and anti-Stokes lines of 3.672 and -0.146nm/MPa, respectively. The proposed sensors have potential applicability in high-pressure environments.