Abstract
A high order harmonic generation optimization system and method in tight focusing geometry is provided. The system and method takes advantage of the additional intrinsic atomic dipole phase mismatch introduced by the rapid laser defocusing. This phase can be precisely controlled by adjusting the aperture of a simple iris to correctly compensate free electron dispersion, resulting in tunable harmonic energy and cutoff extension. The implementation of this method in the laboratory is easy and can be extended to other targets and laser wavelengths.