A Novel Method for Measuring Photo-Induced Birefringence of Photosensitive Fibres Based on a Fibre Loop

We report a novel method for measuring photo-induced birefringence of photosensitive fibres based on a fibre loop. The method is simple and is only slightly affected by the surroundings. The experimental results show that the photo-inducing normalized birefringence of the photosensitive fibre is multi-decaying-exponentially proportional to the exposure and it can attain 10^-5.