Generation of selective fringes with cascaded long-period gratings

The inscription of cascaded long-period gratings of different periods in optical fiber permits us to obtain both narrowband and wideband filters in the same spectrum. If used as an optical transducer, it may permit us to detect with the same device-wide and small parameter changes. The transmission spectra have been simulated using-a theoretical model based on LP mode coupling and have been also experimentally demonstrated.