Multiple volume Bragg gratings with layered structure and their fabrication methods

摘要

Two types of multiple volume Bragg gratings (VBGs) with layered structure are presented. The one is layered by a planar waveguide array (PWA), the other is directly layered by gratings. Both of them can be fabricated by different illuminations in photorefractive materials, photopolymers as well as other photosensitive materials according to the their properties. A single VBG layered by a PWA and two layers of four-superimposed VBGs were fabricated in LiNbO_3:Fe crystals, respectively. It is shown that the layered multiple VBGs and their fabrication methods presented here are reasonable and feasible. Considering the property of the wavelength division multiplexing of the multiple VBGs, the layered multiple VBGs may be used as a potential MUX/DeMUX in DWDM system.