System for amplifying laser beams

Claim 1

A uni-directional laser amplifier system utilizing a diverged, high quality beam composed of either a single, unstructured pulse, or a train of such pulses, amplified to a very high power level over a long, folded amplification path, emerging via a large, elliptical cross-section aperture, the system consisting of: a. two, well spaced rows of amplifying segments of elliptical and progressively increasing cross-sectional area each segment possessing two optically polished, flat end surfaces with the front surface of each segment being anti-reflection coated and its rear surface having either a mirror deposited on it which reflects the laser beam 100%, or having the mirror attached to it and/or separated from the rear surface of the segment by at least half the length of the laser pulse to be amplified so that no pulse overlap occurs in the amplifying medium; b. Each segment orientated at an angle of approximately 45° to the length of its row and at an angle of about 90° to the segment which follows in the same row so that any pair of segments in the row with their front faces facing each other will reflect the diverged beam traversing the amplifier through a total angle of about 180° the beam traversing each segment twice during this process so that it emerges travelling approximately parallel to its path of incident but in the opposite direction and displaced by at least its own diameter in such a manner that it can traverse all remaining segments of the amplifier system; c. Optical excitation sources positioned along each row of segments, matching their respective parameters in both size and power and separated from each other along a row of segments by a pair of segments which turn the beam through the 180° angle, excitation radiation from each output surface of the source except those facing input and output segments, traverse both segments in such a manner that one end of each segment is excited before the other due to the fact that the excitation sources and the segments are orientated with respect to each other by an angle of approximately 45°.