Optical transmitter, method for generating multiple beams and free space optical communication system

Abstract

Optical systems and methods for transmitting multiple beams and directly detecting these beams are described. A transmitter used in a free-space optical communication system includes a broadband light source and an optical component including a plurality of sections positioned to receive a light beam generated by the broadband light source. The sections of the optical component are formed to introduce optical path differences into portions of the beam of light incident on the optical component such that each section introduces a delay into a corresponding portion of the beam of light. The delay introduced makes each part of the beam incoherent from other parts of that beam. A direct detection receiver detects the intensity of the focused beam and produces a signal with an improved signal-to-noise ratio. The disclosed techniques can be used with modulated beams such as intensity modulated beams.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of US Patent Application No. 14 / 984,093, filed December 30, 2015, the entire contents of which are incorporated herein by reference. technical field [0003] The subject matter of the present invention relates generally to the detection of optical signals, and more particularly to the direct detection of multiple optical signals from sources having a broad frequency spectrum. Background technique [0004] A wireless communication system transmits data from a transmitter at one station to a receiver at another station. In some applications, one of the stations may be ground-based (ie, static), while the other is carried by an aircraft (eg, a satellite in Earth orbit, an aircraft, or an unmanned aerial vehicle (UAV)). Additionally, multiple stations may be ground-based and communicate with one or more objects in flight, both stations may be part of the aircraft, or both stations may b...

AI Technical Summary

Problems solved by technology

While experimental FSO technology can now transmit data down at 10Gb / s from air or space, these solutions are complex and expensive, require relatively large components, and consume a lot of power

One challenge associated with free-space optical communications is atmospheric turbulence, which interferes with optical signals passing through most of the atmosphere

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