Improving transmission efficiency of Cassegrain antenna

A special conical lens and photonic crystal reflector are used to increase transmission efficiency of the Cassegrain antenna. Gauss beam is shaped into a hollow beam which could avoid the loss of energy caused by the subreflector center reflection in the Cassegrain antenna, and the transmission efficiency in the space optical communication system will be greatly enhanced. A one-dimensional (1D) photonic crystal reflector is designed to reduce energy absorption. Thus transmission efficiency of the whole system can be almost close to 100% in theoretical aspects. It is pretty significant for space optical communication of transmission long distances.