Detection of distributed polarization coupling in high birefringence fibers

Abstract

White light interferometry has been adopted to measure the distributed polarization coupling in high birefringence fibers. A superluminescent diode is adopted as the optical source in the white light interferometer. To enlarge the measurement range, the light beam in the scanning arm of the Michelson interferometer is reflected three times. Thus the scanning range of the interferometer is doubled. The full-width half-maximum spectrum of the SLD is 50 nm, and the central wavelength is 1300 nm. If the modal birefringence of the HBF is 5×10^-4, a spatial resolution of 70 mm can be achieved. A high sensitivity photo detector and a high-resolution analog to digital converter have been adopted. The polarization coupling intensity measurement accuracy can be up to -75 dB.