| 摘要 |
Many-layered electrooptical material consisting of a quantity of adjacent single crystals possessing varying electrooptical properties. The material is produced by a process in which the layers are formed by epitaxic growth from a liquefied solution of the said electrooptical material, which may contain at least one doping agent. In one embodiment, such an electrooptical material consists of silver thiogallate, and the layers are formed by the epitaxic growth of a liquefied solution of silver thiogallate and potassium chloride, which can contain at least one doping agent. This liquefied solution exhibits the special property that it is possible, for a particular composition of the solution, to form layers having different electrooptical properties by cooling over a temperature range which yields crystal growth with a composition which corresponds to the desired electrooptical properties. It is possible to make use of this temperature/composition phase separation in order to form many layers by first cooling within one temperature range such that a layer of silver thiogallate, which contains the doping agent, is formed on a seed crystal substratum and then forming a second layer having another composition, which can vary from essentially pure silver thiogallate to silver thiogallate which contains at least one doping agent, on this first layer by cooling within another temperature range. If cooling is carried out in turns over these different temperature ranges, it is possible to form many-layered structures in which adjacent layers have different electrooptical properties. The many-layered structures which are formed in the above- described method can be used in electrooptical devices, in particular as the regulatable birefringent medium in regulatable electrooptical filters. <IMAGE> |
