Berichte der Bunsengesellschaft für physikalische Chemie
Spectral Hole‐Burning: Applications to Optical Image Storage
Cosimo De, Alois Renn, Urs P. Wild
Abstract
Abstract Spectral hole‐burning was used to record information in the inhomogeneous broadened absorption band of free base chlorin in polyvinylbutyral at 1.7 K. The wavelength multiplexing property of these materials allows to store many images in the form of holograms in a single spot of about 5 mm diameter. The gray level pattern of the image is translated into a pattern of a spatially varying hole depth. Such a storage device can be considered three‐dimensional, involving the two spatial dimensions of the thin sample film and the dimension of the optical wavelength. If in addition an electric field is applied, a four‐dimensional storage device is created having two spatial, one wavelength and one electric field dimensions. Addressing a specific image is achieved by merely adjusting the read‐out wavelength and the value of the electric field to the values used during the storage process. No moving parts are involved at all. It is demonstrated that in chlorin at least 25 images can be stored in a single 1 cm−1 interval and in the electric field range of ± 100 kV/cm.