Patent ID: 6327284
Filing Date: 2001-12-04
Classification: G01J

Abstract:
An argon fluoride laser system, comprising:a gain medium including a gas mixture of argon, fluorine and a buffer gas for generating a beam of ultraviolet radiation having a wavelength around 193 nm;a discharge unit and a high voltage power supply for supplying energy to the gain medium;a resonator including a wavelength selector for generating a narrowed output beam having a bandwidth of less than 0.6 pm;a detector for measuring an energy of the output beam including a light sensitive element and a frequency conversion coating for absorbing incident 193 nm light and re-emitting light having a wavelength longer than 240 nm in a direction toward said light sensitive element, such that a dark current background, known to grow rapidly when light sensitive elements are used without protective frequency conversion coatings, is suppressed permitting the detector to have a lifetime of more than one billion laser pulses and permitting the laser system to remain on-line to perform continuous industrial processing during the more than one billion laser pulse lifetime of said light sensitive element; anda processor for receiving a signal from the detector indicative of the measured energy of the laser beam, and for sending a signal to the high voltage power supply based on the measured energy to control the high voltage power supply to supply a particular energy to the discharge circuit for stabilizing an energy of the output beam of the laser through a feedback loop including the detector, the processor and the high voltage power supply and discharge circuit.