ELECTROMODULATION OF LIGHT-SCATTERING IN SINGLE-CRYSTALS OF ANTHRACENE

Modulation of light scattering by electric field in anthracene crystal s is reported. Scattered light was that obtained from a He-Ne laser. E ffective modulation of scattered light was possible only when concentr ation of trapped charge carriers was changed by an external electric f ield under space-charge-limited conditions. External voltage character istics of electromodulation signal were structured, the signal height was up to ten percent. The observed effect is discussed in terms of th e modulation of the population of the filled up charge trapping domain s responsible for the light scattering. The change in the local comple x refractive index due to the charge captured by a spatially extended defect (macrotrap) is considered as the most probable microscopic mech anism of the effect.