Influence of pump beam diameter on beam fanning in a doped photorefractive polymer composite

摘要

Beam fanning in a 100 μm thick sample of the photorefractive polymer composite PVK:TNF:ECZ:DMNPAPBE was experimentally studied as a function of pump beam diameter and applied electric field. The normalized increase in fanned beam power was 65% as the ratio of pump beam diameter to film thickness increased by a factor of 3 at constant applied field. The dynamical behavior of the fanned beam was well described as a double-exponential function of time, with grating rise times a factor of 10 longer than those observed for two-beam coupling in similar photorefractive polymer composites.