Empirical relations for far-field characterization of photonic crystal fibers

Abstract To characterize far-field of a solid-core photonic crystal fiber (PCF), we present simple empirical relations for angle of beam divergence of PCF only depending on the opto-geometrical parameters like wavelength of the light used and the two structural parameters – the air hole diameter and the hole pitch. We validate the accuracy of the proposed expressions by comparing the empirical relations with the results of exact values. We can easily evaluate the far-field properties of PCFs through the empirical relations without the need for numerical computations of V parameter or spot size or the effective cladding index.