Multiple aperture laser systems for thermal blooming environments

An approach to improving power densities on target for high-energy laser systems operating in thermal blooming environments is presented. The concept employs small discrete subapertures in place of a large single aperture to reduce thermal blooming effects in the target region. Preliminary calculations indicate that subunit phase control is not essential to achieving adequate performance. Wave-optics computer codes were used to study key performance parameters in addition to predicting target irradiances for several simple (two- and four-subaperture) system models. Improvements of the order of 30 percent in peak irradiances were found, compared with equal total area single apertures. A preliminary evaluation implies that a multiaperture system can be configured to achieve at least comparable performance as a monolithic system but with smaller less costly optical elements.