Research On The Aspherical Optical Replication Technique

The technique of aspherical optical replication is one of the techniques of producing optical aspherical surfaces with high efficiency and low cost put forward in 1980's. It is a technique producing aspherical lenses by moving surface shape. A surface with a high precision is transferred from an aspherical optic (the mold) to a surface of a spherical one (the substrate) with the help of release and adhesive, at the condition of maintaining its optical quality. During this process, the spherical surface is changed into an aspherical one. Compared with other methods of making aspherical lenses, this technique has outstanding advantages. Firstly, it needs only simple equipment; the optical surface of the substrate doesn't need to be polished, which reduces the producing cost greatly and promotes the efficiency of the production, thus overcome the weakness of making aspherical lenses one by one. Secondly, the surface of the substrate is spherical, which can be easily made; the duplicating layer is very thin, so the replica has good environmental endurance. In addition, a mold can be used time after time; it's consistence of the parameters is good, and this makes the technique of replication applicable for the mass-production of the segmented mirrors used for putting together and lenses with same standard. In this article, based from the fundamental of the aspherical optic replication technique, the technical process is discussed. The applicable scope of this technique is analyzed considering the nature of the materials, and the corresponding dimension of the substrate is designed to different figure lenses. Also, special clamps used for jointing and separating are designed. Then, combined with the vacuum film plating theory, adhesion theory and the un-molding mechanism, several technical experiments (coating, un-molding and gluing etc.) are emphasized, and the surface graphs of the replica replicated on the polished substrate and the un-polished gross substrate are given. Also, the precision of the mold's surface is compared with after the replicating process, and the conclusion has been obtained that the figure of the mold's surface after being used many times doesn't decline, and it is almost immune to the process. Moreover, the figure of the replica's surface is nearly accordant with the mold, and it reflects the mold's surface precision. Therefore, the result testifies that this technique is feasible for the production of middle and small aspherical lenses with high accuracy.