PQ/PMMA holographic filters for OCDMA over CWDM Applications

摘要

Multiple users could be multiplexed into a single Coarse Wavelength Division Multiplexing (CWDM) channel of metropolitan area networks using an Optical Code Division Multiple Access (OCDMA) scheme increasing the totalnumber of users of the system. Thermally tunable holographic filters operated using an edge illuminated transmissionhologram configuration, can provide a compact and tunable solution for this application. The filters are realized by athick unslanted grating. The gratings are recorded in PQ (phenanthrenequinone)-doped PMMA (polymethylmethacrylate) photopolymer substrate in a holographic setup. The gratings are designed to filter light from thepropagation direction for specific segments of a CWDM channel. The filters can be thermally tuned using thermo-electric cooler plates to change the period of the grating. In this paper we present the construction and performancecharacteristics of these filters.