A new photorefractive imaging X-ray sensor

We present a new concept for an imaging X-ray sensor based on X-ray-induced hologram erasure. A transmission hologram is recorded by two plane waves in a photorefractive lithium niobate crystal. This hologram acts as a sensor plate that is positioned towards the X-ray radiation like a conventional X-ray film. Spatially modulated X-ray illumination produces a spatially modulated conductivity that erases the hologram. By these means, a hologram with spatially modulated diffraction efficiency is obtained. Reading of the hologram with a plane wave of visible light then yields in the diffracted beam a replica of the original X-ray light pattern. First experimental data are presented. High spatial resolution, limited in principle just by the wavelength of the probe light, together with a time integrating behavior are the main advantages of such a detector.