Adaptive Optics for Nonlinear Atmospheric Propagation of Laser Pulses

Ultra-short pulse lasers have advantages over continuous-wave lasers for directed-energy applications due to the high peak powers that can be reached. Directed-energy weapons are profoundly limited by the aberrations caused by atmospheric turbulence and current adaptive optics can correct for these aberrations only when the propagation medium is reciprocal. Unfortunately, nonlinear effects in the propagation of ultra-short laser pulses causes a breakdown in reciprocity between a lower power beacon and a high power beam. Toyon Research Corporation and University of Maryland, College Park are proposing an adaptive optics concept where a partially coherent beacon informs the adaptive elements of the corrective distortions to pre-apply to the high power beam. The proposed adaptive optics concept is suitable for use with ultra-short pulse lasers.