Feedback-controlled recording and fixing of photorefractive holograms in reflection geometry on lithium niobate crystals

A digital feedback control loop system is used to produce high-efficiency photorefractive gratings in reflection geometry for volume narrow band reflection filters. The system allowed hologram recording up to saturation. Several strategies are investigated to obtain higher fixed efficiency. A double controlled recording/fixing process with stationary fringes produced holograms with fixed efficiency higher than 90%. This method is interesting for producing reproducible high-reflectivity narrow band reflection filters of customized wavelength in the visible and near-infrared regions. (C) 2011 Optical Society of America