Spectral phase OCDMA encoder/decoder using Travelling Interference Fringe photo-writing technique

In this paper, we describe and investigate a new UV photo-writing setup using Travelling Interference Fringe (TIF) technique for Fiber Bragg Grating (FBG) realization. A continuously moving fringe pattern is generated using two electro-optical UV modulators and is synchronized with the fiber moving speed. FBG parameters such as chirp, phase shift and apodization profile can be controlled with high precision. This method is used to realize repeatable, flexible and complex profile spectral phase OCDMA encoders/decoders. Experimental realization results in good agreement with numerical simulations are presented and discussed. The obtained encoders/decoders are tested within a system setup using a supercontinuum optical source.