Research On Krf Ase Short Pulse Obtained By Laser Oscillation Quenching

The KrF excimer laser is used as one of the driven sources for researching on the inertial confinement fusion (ICF). The findings indicate that pulse with width of 1-10ns is the most appropriate pulse in ICF experiment. However,the initial pulse width of KrF is larger than ten ns. So it is necessary to compress the output pulse of KrF. ASE.In this paper, KrF. ASE short pulses with width less than 10ns are obtained by technologies of laser oscillation quenching with one mirror and two mirrors. The influence of relative parameters on pulse chopping is investigated.Based on the transmission theory of laser pulse amplification, the theoretical model of ASE short pulse generated by laser oscillation quenching is established. Then, comparison of original pulse and compressed ASE pulse as well as the influence of pump voltage on the ASE pulse shape are analyzed. Finally, The relationship between parameters such as the angle and distance between the cavity mirrors and ASE short pulse are provided.In experiment, the original pulse and ASE pulse with one or two reflecting mirror are researched. It is demonstrated from the experimental result that for the original ASE pulse, pulses with width less than 10ns are obtained when output aperture is 1 to 10mm, and pulses with width from 7.3 to 7.4ns are obtained when output aperture is from 5 to 6mm; for pulse compressed with two cavity mirrors, when the former cavity mirror is set bias, with increasing of distance between cavity mirrors, the duration of ASE pulse firstly increases and then decreases, and the optimistic compression is under the distance of 2mm, which is 9ns compressed from 32ns; for pulse compressed with one cavity mirror, when the former cavity mirror is took off, with increasing of angle between two cavity mirrors, the duration of ASE pulse firstly decreases and then increases, and the optimistic compression is under the angle of 3.8mrad, which is 4.2ns compressed from 7.6ns.The beam quality of output ASE pulse is investigated with beam quality analyzer. The results indicate that the in-homogeneity of the beam remains the same within 2% when the aperture is different, while the output energy increases with increasing the aperture. In sum, with the consideration of capacity usage ratio and compression ratio, the optimistic aperture would be 5~6mm.