Experimental characterization of the spectral effective index dependence of index-guided photonic crystal fibers

Abstract

The effective index of index-guided photonic crystal fibers (IG-PCFs) is experimentally obtained as a function of the wavelength by writing fiber Bragg gratings (FBG) in the fibers. The results are found to be in good agreement with theoretical simulations and are also discussed and compared with measurements on standard telecommunication fibers. Differences between the fibers were observed both in the Bragg grating inscription process and in the evolution of the fiber effective index value with the wavelength, which depends on the fiber cladding microstructure. Index evolution slopes of −2.029 × 10−5 nm−1, −2.044 × 10−5 nm−1 and −1.388 × 10−5 nm−1 were measured for two IG-PCFs and the standard fiber, respectively.