The (polymer/liquid-crystal) composite films have the phase-separated structure that liquid crystals are embedded in the three-dimensional polymer networks. The composite films exhibit the reversible switching of light scattering-light transmission by an electric field at visible light wavelength region. Those optical properties are applied in a light valve device. In this study, we prepared the (polymer/liquid-crystal) composite films doped with a dichroic dye in order to develop a light-shutter function in optical communication wavelength region. We investigated an electro-optical properties and polymer network structure of the (polymer/liquid-crystal) composite films and discussed the mechanism of them.