A peripheral video conferencing system is housed in a peripheral housing and adapted for communication with an analog or digital communication channel and a separate host computer system. The additional information is a plurality of representative frames from the moving image, each representative frame being a still image representing a group of sequential frames, and an implicative image associated with at least one frame in the group of sequential frames other than the representative frame. The method comprises: a step of preparing a ferrite sheet; and step of placing a heat-dissipating layer on one side of the ferrite sheet. The second image information of the object is obtained at the second focus. Preferably active ions selected from the group of the rare-earth elements are incorporated into the crystalline phase of the composite to provide the glass ceramics with luminescent up- and down-converting characteristics.