Photonic solution to phase sensing and control for light-based interstellar propulsion
Chathura P. Bandutunga, Paul G. Sibley, Michael Ireland, R. L. Ward
Abstract
Reaching another star system within a human timescale requires traveling at a sizeable fraction of the speed of light. To achieve this, the Breakthrough Starshot program proposes a ground-based laser array to accelerate a gram-scale spacecraft through photon radiation pressure, requiring of order 100 GW of continuous wave optical power. The coherent combination of many lasers is one avenue to achieve a high optical power output. Here we present a photonic solution for optical phase sensing and control to enable the coherent combination of order <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>8</mml:mn> </mml:msup> </mml:mrow> </mml:math> individual lasers, including the ability to sense and compensate for atmospheric distortions, assuming the laser system is ground based.