Beam propagation simulation of phased laser arrays with atmospheric perturbations

Abstract

Directed energy phased array (DEPA) systems have been proposed for novel applications such as beaming optical power for electrical use on remote sensors, rovers, spacecraft and future moon bases, as well as planetary defense against asteroids and photonic propulsion up to relativistic speeds. All such scenarios involve transmission through atmosphere and beam perturbations due to turbulence which must be quantified. Numerical beam propagation and feedback control simulations were performed using an algorithm optimized for efficient calculation of real-time beam dynamics in a Kolmogorov atmosphere. Results were used to quantify the effectiveness of the system design with different degrees of atmospheric turbulence and zenith angles, and it was found that a large aperture DEPA system placed at a high altitude site is capable of producing a stable diffraction limited spot (Strehl > 0.8) on space-based targets for Fried length r_0 > 10 cm (@500nm) and zenith angles up to 60 degrees depending on atmospheric conditions. These results are promising for the next generation of power beaming and deep space exploration applications.