SPACE-CHARGE FIELD ENHANCEMENT IN PHOTOREFRACTIVE MATERIALS BY APPLIED SINUSOIDAL FIELDS - AN APPROXIMATE ANALYTICAL SOLUTION

The second order temporal differential equation, known to describe the space charge field in the high frequency region, is solved approximat ely in a closed analytical form. The condition for multiple resonances is found. The maxima and minima in the space charge field are shown t o correspond to the roots of the zero and first order Bessel functions respectively. The analytical approximations for the space charge fiel d are compared with numerical results for the complete range of freque ncies, and it is shown that there is excellent agreement between the t wo for the high frequency region which includes all the resonances.