Novel dispersion compensation method for cross-coupling measurement in PM-PCF based on OCDP

• Inter-mode chromatic dispersion coefficient of PM-PCF is simulated and measured for the first time.
• A dispersion compensation method in frequency-domain is proposed for OCDP result.
• Coupling strength and spatial resolution can be recovered simultaneously with high accuracy.
• Only raw data of interference signal and dispersion coefficient are utilized in compensation.

For polarization maintaining photonic crystal fiber (PM-PCF), the cross-coupling measurement can be severely affected by interferogram broadening, due to the large inter-mode chromatic dispersion. In this paper, a novel dispersion compensation method is proposed to mitigate the influence, including a frequency domain algorithm and investigation of the dispersion coefficient for a phase packet in algorithm. A numerical simulation and measurement of birefringence as a function of wavelength reveal that the dispersion coefficient in PM-PCF is much larger than that in PANDA-PM fiber. After compensation, the accuracy of coupling strength measured can be restored and spatial resolution is improved. Experiments show the compensation provides high accuracy with average relative error less than 0.31% and spatial resolution improved 4.1 times.