Characteristics Of E-Beam Pumped Krf Laser System

Abstract

The charcteristics of strongly saturated amplifier with a 100ns electron beam excitation are studied to determine the small signal gain, non-saturable absorption, and saturation intensity from 6% Kr to 95% Kr in Ar diluent. The pumping rates are maintained constant by adjusting the total pressure of gas mixtures to conpensate the different stopping power of Ar and Kr. Non-saturable absorption coefficients are measured at a full saturated amplifier between the zero gain intensity to 80MW/cm2. The small signal gain of 12.9%/cm and non-saturable absorption coefficient of 1.32%/cm2 are obtained for 95% Kr mixture. The saturation intensity, 2.2MW/cm2 for 6% Kr and 2.9MW/cm2 for 95% Kr mixture, derived from the zero gain intensity is in good agreement with the prediction of our computer model. Highest intrinsic efficiency of 12.2% is measured at high Kr concentration where the Extraction power density of 6.8MW/cm2 is obtained by the probe laser beam between 5-6MW/cm2. The formation efficiency for a wide range of Kr concentrations agrees with the theoretical prediction excellently as a function of Kr concentration. The details of the important parameters, gain , absorption, saturation intensity, maximum output, intrinsic efficiency, extraction efficiency, and formation efficiency will be discussed in this paper.