Patent ID: 6549555
Filing Date: 2003-04-15
Classification: G03F,H01S

Abstract:
An excimer or molecular fluorine laser system, comprising:a discharge chamber containing a gas mixture; a plurality of electrodes connected to a power supply circuit for energizing the gas mixture; a resonator for generating a laser beam; a processor; and an amplified spontaneous emission (ASE) detector, and wherein the processor receives a signal from the ASE detector indicative of the ASE signal of the laser, and wherein said ASE detector detects a filtered signal, wherein a substantial portion of a stimulated emission signal of the laser beam is filtered from the laser beam prior to monitoring said ASE signal, and wherein said ASE detector comprises a stimulated emission filter for substantially filtering the stimulated emission from a portion of the laser beam to permit the ASE signal to be resolved from the laser beam, such that the proportion of the ASE signal within the beam portion upon being filtered at said stimulated emission filter is increased to more than 2%.