As the advancement of photonics, holographic optical elements (HOEs) have become important in various applications. Some of their products have already been commercialized. Currently bar code reader, as used in supermarkets is one good example. The zone plate is essential in the search for HOEs. Therefore, in this study, we aim to investigate the basic characteristics of zone plates by means of active scanning, so as to provide adequate evidence in fabricating specific HOEs. From this experiment we are made aware that the extended zone plate has a good effect in linear scanning and focusing.