Integration of Volume Holographic Optical Elements (vHOE) made with Bayfol® HX Film into Plastic Optical Parts

摘要

See-through optical components are being intensively studied in applications such as Head-Up-Displays (HUD) andHead-Mounted-Displays (HMD). In particular, volume holographic optical elements (vHOE) have received a lot ofattention due to their unique optical (angular and spectral selectivity) and mechanical (lightweight and thin)characteristics which make them perfectly suitable for use in integrated optical components like spectacle lenses and carwindshields. Bayfol® HX photopolymer films prove themselves as easy to process recording materials for vHOEs. TheBayfol® HX instant developing holographic photopolymer film provides full color capability and adjustable diffractionefficiency as well as an unprecedented optical clarity when compared to classical volume holographic recordingmaterials like silver halide emulsions (AgX) or dichromated gelatin (DCG). Besides the recording step, no pre- or postprocessingis necessary and easy mass production of vHOEs in a completely dry roll to roll process is possible.The layout of a typical Bayfol® HX film consists of a light-sensitive photopolymer layer coated onto a transparentthermoplastic substrate. This substrate is particularly beneficial, not only for easy handling of the film duringholographic recording, but also for further mechanical processing steps which are required to embed the film into afinished optical component. Once holograms have been recorded and the film has been bleached with incoherent light,the Bayfol® HX film becomes inert and can be further processed in normal daylight. Moreover, the presence of athermoplastic substrate makes the film attractive for use in manufacturing processes such as injection molding,thermoforming, casting, etc…, typically used to fabricate parts for the automotive, eyewear and ID-card industry. Beingcompatible with these industrial processes is an essential feature for the widespread of immersive Augmented Realitydisplays based on volume holographic optical elements recorded into Bayfol® HX films. In this paper we investigated thecompatibility of holograms made with Bayfol® HX film with some of the integration processes typically used in theplastic and optical components industry and which are necessary for embedding the holographic films into a finishedproduct.