Effects of fiber cladding diameter on cladding-mode coupling in fiber Bragg gratings

Abstract

The effects of cladding diameter on cladding-mode coupling in fiber Bragg gratings are investigated both theoretically and experimentally. The peak depth induced by the cladding-mode coupling increased with decreasing cladding diameter whilst the number of cladding-modes coupled from the core mode decreased. The wavelength spacing between the main peak and the first-order cladding-mode increased as cladding diameter decreased.