The simultaneous application of low intensity optical and static electric fields to photoisomerizable electro-optic materials is shown to allow manipulation of the refractive index. A dc electric field was applied to the sample by means of a corona poling mechanism, which was illuminated within the absorption band using a low power laser. The application of the optical field caused a reduction in polar order in the material, with a corresponding change in the refractive index. The change of polar order was monitored by optical second harmonic generation. For typical experimental values, the variation in refractive index was calculated to be about 1&percent;, which is sufficient to change waveguiding conditions. Electroded samples also showed the effect. ©1998 American Institute of Physics.