Phase shifted and cascaded long-period fiber gratings

We have obtained useful analytical expressions for the spectra of phase shi fted and cascaded long-period gratings and have demonstrated experimental r esults which are in good agreement. We discuss how the introduction of a ph ase shift allows the tailoring of the transmission spectrum of a long-perio d fiber grating and how cascading two long-period gratings gives multiple t ransmission peaks in the band of the grating spectrum. (C) 1999 Elsevier Sc ience B.V. All rights reserved.