Spectral interferometric measurement of a birefringence photonic crystal fiber

Abstract

Dispersion properties of photonic crystal fibers, important in many applications might differ from the desired specifications due to deficiencies in the manufacturing process, thus an experimental verification is indicated. In this paper the possibility of measuring the birefringence of a polarization-maintaining photonic crystal fiber by using an interferometric-spectral technique is demonstrated. The polarization-preserving photonic crystal fibres used belong to different manufacturers and exhibit high birefringence values, ranging from 5.7x10-4 to 6.7x10-4, when operating in the vicinity of 1550 nm. Different Sagnac interferometers were made with loops of polarization preserving fibres having different values of birefringence and length L, consequently producing diverse spectra of transmittance. A high precision optical spectrum analyzer was applied for spectral data recording, allowing to calculate the properties associated to each scheme of birefringence photonic crystal fibre. In our case, the experimentally measured values fell within the value ranges given by the manufacturers.