High sensitive pulse measurements using nonuniform quasi-phase matching gratings

Some experiments of optical performance monitoring (OPM) with uniform or nonuniform quasi-phase matching (QPM) gratings waveguides have already been demonstrated during the last few years. Theoretical analyses based on coupled-wave equations are carried out for nonuniform QPM gratings. The generation process of SHG in nonuniform QPM gratings is simulated and the outcome comparison between uniform and nonuniform QPM gratings, which demonstrate that nonuniform QPM gratings are more suitable for the OPM systems, is carried out in this paper. The value of grating chirp coefficient of the chirped PPLN has influence on the efficiency and band width of the output pulse. The relation between them is also discussed. These are new simulative attemptation to apply the nonuniform quasi-phase matching gratings into optical performance monitoring system.