Expanding beam concept for building very large excimer laser amplifiers.

Optical extraction efficiency from conventional lasers and amplifiers with nonsaturable intrinsic absorption is substantially below the maximum efficiency at absorption length products exceeding unity. This result is caused by the fact that high intensities in the amplifier cause saturation of gain but not absorption. In this letter, a new scalable amplifier concept is analyzed which maintains near maximum extraction efficiency as the laser length increases beyond absorption length products of unity. [ABSTRACT FROM AUTHOR]