Lookthrough Compression Arrangement

Abstract

An apparatus and process for pumping laser media by an optical pump over a 10 nanosecond period and thereafter time compressing the energy into an extraction pulse and focusing onto a target with a final 1 nanosecond irradiation time are disclosed. The exciting pump pulses are directed into a lookthrough compression arrangement wherein they energize a stimulated scattering process in low pressure (about 1 atmosphere) gaseous media and impinge in an off axis backward geometry. The extraction pulse is formed and directed towards the target with the appropriate information (color, phase, desired irradiance pattern) impressed on it at relatively low energy by manipulation with conventional, solid material optical elements. Once formed, it traverses the gaseous media, is amplified, and proceeds through a vacuum transition section and onto the target. After the injection of the extraction pulse into the lookthrough compression arrangement, it is amplified in the gaseous media by conversion of the pump energy, coupled through the scattering process. The media and the pump and extraction pulses are tailored to give high energy gain to the input optical pulse, high output fluence, good beam quality (high fidelity amplification to the desired temporal and spatial shape), and time compression. Once injected into the entrance to the first section by the material elements, the extraction pulse proceeds through shutter areas that separate different media regions and encounter no further solid material optical elements as it travels to the target. The focus on the target is impressed before amplification and time compression from the pump pulses and results in a very high brightness irradiance of the target. The desired spatial pattern of irradiance on the target is likewise formed with material elements and then imaged onto the target. Fluences some 2-3 orders of magnitude above those available under the conventional art may be thus obtained with an output brightness better by some six orders of magnitude.

Dependencies are inferred from the claim text.