Document Type : Research Paper
Authors
Abstract
A self-filtering unstable resonator (SFUR)with a magnification of M=-3 in a Nd:YAG(2ω)dye laser has been studied.The dye solution is Rhodamine 6G in alcohol with theconcentration of 5 ×10 -3 Mol/lit. The spatial intensity distribution of the resonator has been compared with that of a plane-parallel (PP) resonator of equal length. The output energy in both configurations are comparable (20 μЈ ,and 26μЈ ,respectively). A significant difference between these two resonators is the laser beam divergence, where beam divergences of 0.77 mrad for the SFUR and 1.6mrad for the plane-parallel resonator have been measured. The brightness corresponding to these two resonators are 1.5× 1011 and 2.2× 1010 W.cm-2.Sr-1, and the pulse widths are 7 and 17 ns, respectively. These figures show clearly that laser resonator based on the SFUR design can increase the laser brightness by a factor of 10,with a beam divergence of a fraction of mrad, compared with the plane-parallel resonator. In order to describe the dynamic behavior of the SFUR design, a numerical calculation based on the rate equations have been used and a good consistency with the experiment has been obtained.
Highlights
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Keywords
11. M. R. Perrone and A. A. Flippo, “Experimental characterization of high magnification self-filtering unstable resonators for XeCl laser,” Optics Commu. 88, 115 (1992).
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