Interferometric assessment of induced nonlinear susceptibility in perturbed single-mode optical fiber for all-optical switching

Abstract

The induced variations of complex third-order susceptibilities in bent single-mode fiber at the standard operating wavelengths, 1300 and 1550 nm, is studied using Fizeau interferometry for radius of curvature ranges from 5 to 11 mm. At λ = 1300 nm and at the minimum radius of curvature R = 5 mm, the cladding real (dispersive) third-order susceptibility Re|χ(3)| = 1.167×10−15±0.8% electrostatic unit (esu) on the tensile side, whereas on the compressed side it is 1.309×10−15 esu. On the tensile side, the cladding imaginary (absorptive) third-order susceptibility Im|χ(3)| = 2.089×10−18±0.8% esu, whereas on the compressed side it is 2.118×10-18 esu. For λ = 1550 nm, the cladding Re|χ(3)| and Im|χ(3)| on the tensile side are 1.116×10-15 esu and 2.478×10-18 esu, whereas on the compressed cladding side they are 1.259×10-15 esu and 2.514×10-18 esu, respectively. At λ = 1300 nm and R = 5 mm, the core Re|χ(3)| is given by 1.318×10-15 esu on the tensile side and 1.324×10-15 esu on the compressed side. The asymmetry in Im|χ(3)| is given by 4.687×10-17 esu on the tensile side and by 4.89×10-17 esu on the compressed side. With λ = 1550 nm, the core Re|χ(3)| asymmetry is given by 1.267×10-15 esu on the tensile side and by 1.272×10-15 esu on the compressed side. For Im|χ(3)| its core asymmetry is provided by 5.561×10-17 esu on the tensile side and by 5.564×10-17 esu on the compressed side. The observed asymmetry in the measured complex third-order susceptibility components for bent fibers is attributed to the nonlinear response of Young's modulus of fiber material.