Enhancement of signal-noise-ratio in a distributed polarization mode coupling detection system

A distributed polarization-mode coupling measurement system was designed and implemented using white light interferometry. It can be used for the measurement of polarization mode coupling in a high-birefringence fiber of up to 1 km. This system can be used in both fiber-optic sensors and optical fiber communications. Wavelet Transform was adopted in data processing to improve the signal-noise-ratio. The signal-noise-ratio of this system was improved more than 15 dB after denoising. The influence of denoising threshold on signal-noise-ratio and measurement accuracy was also discussed. Hilbert Transform and non-linear regression can be used in conjunction with Wavelet Transform to enhance the signal-noise-ratio and spatial resolution of this system