High aperture lens for laser compression experiments: a new type

The design and manufacturing requirements for lens systems used in high-power IR laser systems in plasma compression experiments are reported. Such lens systems have a relative aperture of approximately f/1 and an aperture diameter of about 100 mm. The lens must collect a 10.6-micron pulsed laser beam of 100-mm diameter and focus it with a convergence angle of about 25 degrees. The glass must have a low nonlinear coefficient so that nonlinear effects and localized defects will be avoided. Possible lens configurations are described, including: (1) an F/1 aspheric singlet lens, (2) an F/1 aspheric singlet with an auxiliary zero power system for null correcting in the visible, (3) an F/1 aspheric doublet where the aspheric component is null figured in the visible without the meniscus, and (4) an F/1 aspheric doublet where the aspheric surface is null figured in the visible with an air space of 8.6 mm.