Hologram fixing process at room temperature in photorefractive Bi12SiO20 crystals

Abstract

We present the first demonstration of a room-temperature grating fixing process in a photorefractive Bi12SiO20 crystal. This arises from a space-charge compensation due to a hole conduction when the crystal is placed in the dark for 1–3 min. The grating is optically revealed by redistribution of photoelectrons through the uniform illumination of the crystal. After compensation and optical revelation, the readout time constant of the grating is increased by a factor of 40×. Electrical revelation of fixed gratings and holographic images is also demonstrated.