Active optical zoom for laser communication

Abstract

Changing the field-of-view of a laser communication system in real-time without mechanical motion could significantly improve signal strength and reduce drop out rates. By incorporating active elements into the optical design, we have designed and demonstrated imaging systems that are capable of variable effective focal lengths with no macroscopic moving parts (i.e. active optical zoom). This technique, in which the active optics serve as variable focal-length lenses, could easily be applied to laser communication systems to improve capability. The key to this concept is to create relatively large changes in the field-of-view of the system with very small changes in the focal lengths of individual elements by leveraging the optical power of conventional optical elements surrounding the active optics. By appropriately designing the optical system, these variable focal-length lenses can provide the flexibility necessary to change the overall system focal length, and therefore field-of-view, that is normally accomplished with mechanical motion in conventional zoom systems.