A two-step scanning-mask exposure method for the fabrication of arbitrary apodized fiber gratings

A novel two-step exposure method for the fabrication of apodized fiber Bragg gratings (AFBG's) with arbitrary apodization functions has been proposed in this paper. The method can be fulfilled by two-step exposures with specially designed apodization and compensation masks for each step, respectively. The masks were driven by a motor which was program controlled according to the desired apodization function. For the sake of validation, three types of AFBG's, with Linear, Gaussian, and Nuttall apodization functions, respectively, have been experimentally fabricated using the proposed method, and the effects of some unideal experimental setups on the reflection spectra of the FBG's were analyzed and discussed.