Photorefractive and Photochromic Effects in Barium Titanate

Nominally undoped p-type Barium titanate was grown that exhibits interesting intensity dependent photorefractive and photochromic properties. When its photochromism is activated the absorption increases at the activating wavelength and there is a concurrent and proportional reduction in photorefractive response time. Three photoactivated and thermally reversible absorption conditions and the difference spectra of the photochromic crystal are shown in Figure 1.
This article is from 'Organization of the Optical Society of America Photonic Science Topical Meeting Series. Volume 14. Photorefractive Materials, Effects, and Devices Held in Beverly, Massachusetts on 29-31 July 1991,' ADA253001, p351-354.