Apodization compensation of sampled Bragg grating by off-coherent zone second exposure

Numerical results show that only apodization compensation is necessary for apodized binary sampled Bragg grating, while sampling compensation is not necessary. A novel off-coherent zone preconditioning approach is proposed which does not require to remove the phase mask. Experiments demonstrate the apparent improvements in the quality of reflectivity and group delay spectrum. [Copyright &y& Elsevier]