Improved contact lens

摘要

The contact element (4b) has an optical plastic, and is partly translucent. The contact element determines a wave front error of half, one-fourth or one-tenth of maximum femtosecond laser beam (1,3) in a passing through ray of light. The contact element determines the wave front error in the passing through ray of light in a wavelength range from 1000 Nm to 1200 Nm. An independent claim is also included for a femtosecond laser system.