Control of optical damage in reduced LiNbO3 by external applied field

The correlation between the susceptibility of refractive index damage (optical damage) and photoconductivity, and the effect of external applied field have been studied in reduced LiNbO3. The magnitude of the photocurrent is proportional to the refractive index changes. The photocurrent and the optical damage vary with the external applied field depending upon the value of the built‐in internal field. The values of the built‐in field which causes optical damage have been estimated from the extrapolation of the photocurrent and the refractive index change versus the external applied field curves. It turns out that optical damage in reduced LiNbO3 can be easily controlled by applying an external field.