Arrangement to reduce fouling of window of gas discharge laser; has heating arrangement to heat at least part of inner surface of window above temperature of laser gas in laser tubes

摘要

The arrangement has a heating arrangement to heat at least part of the inner surface of the window (24) above the temperature of the laser gas in the laser tube (10). The heating arrangement has a closed region connected by an inlet (34) and an outlet (30) to the laser tube and a device to move laser gas through the inlet into the closed region and past a heater through the outlet near the window. An Independent claim is included for a method of reducing the fouling of a window of a gas discharge laser.