High power deep ultraviolet laser with long life optics

摘要

The present invention provides long life optics for a modular, high repetition rate, ultraviolet gas discharge laser systems producing a high repetition rate high power output beam. The invention includes solutions to a surface damage problem discovered by Applicants on CaF2 optics located in high pulse intensity sections of the output beam of prototype laser systems. Embodiments include an enclosed and purged beam path with beam pointing control for beam delivery of billions of output laser pulses. Optical components and modules described herein are capable of controlling ultraviolet laser output pulses with wavelength less than 200 nm with average output pulse intensities greater than 1.75x10<6 >Watts/cm<2 >and with peak intensity or greater 3.5x10<6 >Watts/cm<2 >for many billions of pulses as compared to prior art components and modules which failed after only a few minutes in these pulse intensities. Techniques and components are disclosed for minimizing the potential for optical damage and for reducing the pulse energy density to less than 100x10<-6 >J/cm<3>. Important improvements described in this specification have been grouped into the following subject matter categories: (1) Solution to CaF2 surface damage discovered by Applicants, (2) description of a high power ArF MOPA laser system, (3) description of beam delivery units, (4) polarization considerations (5) a high speed water-cooled auto shutter energy detector module and (6) other improvements.