Measurement of high-birefringent polarization-maintaining fiber and its analysis with Mueller matrix

In order to measure the beat length of high-birefringent polarization-maintaining fibers,an all-fiber optic system,comprised of broadband light source, in-line polarizer with polarization-maintaining pigtail and optical spectrum analysis, was be constructed based on conoscopic interference effect.The expression of optical intensity arrived at the optical spectrum analyzer was derived with Mueller transfer matrix.The measured data of the beat length of a kind of panda high-birefringent polarizationmaintaining fiber was acquired in experiments.It is found that the intensity fluctuation due to conoscopic interference effect makes the spectrum variance in a certain period.The relative amplitude of the spectrum variance is decided by the angles between the chief axes of the polarization-maintaining fiber and the pigtail of in-line polarizer.When the angle is ±45°,the relative amplitude is maximal.Hence,the beat length of the panda high-birefringent polarization-maintaining fiber can be calculated as long as the spectrum fluctuation period is measured in experiments.