Point-to-multipoint free-space wireless optical communication system

Abstract

A free-space wireless optical communication system is disclosed that utilizes a telescope design having aspherical mirrors, such as a Ritchey-Chretien (RC) telescope. RC telescopes are characterized by a concave primary mirror and a convex secondary mirror each having a hyperbolic shape. The disclosed mirror configuration provides a larger focal plane that allows for automatic alignment between a transmitter and receiver with a stationary or fixed mirror design, further contributing to a lower fabrication cost. Among other benefits, the larger focal plane permits an n×n fiber array to be positioned in the focal plane of the RC optical telescope, thereby enabling point-to-multipoint communications with a single optical telescope. Each fiber in the n×n fiber array of a transmitting telescope can be focused on a different receiving telescope in a wireless optical communication system. In this manner, each fiber in the n×n fiber array sends optical energy over a distinct path to address a given receiving telescope. Likewise, for a multipoint-to-point communication system, an n×n fiber array can be positioned in the focl plane 330 of the RC optical receiving telescope, with each fiber in the n×n fiber array receiving optical energy over a distinct path from a given transmitting telescope. A number of fabrication techniques are also disclosed that permit the optical telescopes of the present invention to be fabricated at a reasonable cost that permits such optical telescopes to be deployed in wireless optical communication systems.