Modular interference characteristics and beat length of a two-hole photonic crystal fiber

We show the mode propagation characteristics of fundamental and second-order modes in a two-mode highly birefringent photonics crystal fiber (HB-PCF) under a longitudinal strain. The two-mode operation range in HB-PCF is researched. Within this range, the modular interference beat length L MB in each Eigen polarization are simulated with respect to wavelength λ , and the fitting equations between L MB and λ are presented. We also measure L MB at λ = 532nm , respectively. The results show that the theoretical simulation is basically in accordance with the experimental data.