57 / 2020-02-26 15:15:39

Influence of He mixture on the output of Ne-like Ar 46.9 nm laser under gain saturation

capillary discharge,46.9 nm laser,auxiliary gas He,spatial distribution

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Influence of He mixture on the output of Ne-like Ar 46.9 nm laser under gain saturation
Yongpeng Zhao,1 Dongdi Zhao,1 Qi Yu,1 Muhammad Usman Khan,1 Haiqiang Lu,1 Jingjun Li,1 and Huaiyu Cui1,*
1National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin, 150080, China
*Email: cuihuaiyu_hit@163.com
Since the Rocca team tried to mix H2 into pure Ar in the capillary discharge experiment in 1994, few studies have been carried out on the generation of 46.9 nm laser by mixing gases. Our group studied the influence of auxiliary gas He on the laser pulse and found that appropriate pressure of He can increase the laser pulse amplitude. In that experiment, we didn’t realize gain saturation of the 46.9 nm laser. On this basis, we expanded another experiment on the effect of the auxiliary gas He on the 46.9nm laser pulse amplitude and spatial distribution of 46.9 nm laser under gain saturation
In the experiment of Ne-like Ar 46.9 nm laser produced by capillary discharge, the Influence of He mixture on the output of Ne-like Ar 46.9 nm laser under gain saturation was studied. First of all, the change of laser pulse amplitude with the addition of He was measured by XRD (X-ray diode). It was found that the laser pulse amplitude increased first and then decreased with the increase of the pressure of He, which proved that the laser output could be increased by adding appropriate He. In order to explore the reason of the change of laser pulse amplitude caused by the addition of He, the spatial distribution of laser spot was measured by CCD (Charge-coupled Device). Under the condition of gain saturation of 46.9 nm laser, the laser spatial distribution changed gradually with the addition of He into pure Ar. In order to analyze the influence of the addition of He into Ar on the spatial distribution of laser spot, the theoretical simulation was performed. Findings of this simulation suggest that addition of He affects the plasma state. Therefore, the laser pulse amplitude and spatial distribution changed under the condition of gain saturation of 46.9 nm laser by adjusting the pressure of auxiliary gas He. In other words, different laser spatial distribution can be obtained under gain saturation by properly adjusting the pressure of auxiliary gas He. This is the first experimental as well theoretical study on the spatial distribution of 46.9 nm laser as with Ar-He mixture.

Keywords: capillary discharge, 46.9 nm laser, auxiliary gas He, spatial distribution