Uncovering the Role of Excited States of Dication in Controlling the Dissociative Double Ionization of Ethane

With the aid of newly developed coincidence detection imaging system, we demonstrate that the branching ratios of dissociative double ionization channels of ethane can be controlled by varying the ellipticity of the intense ultrashort laser pulses. The CH₃⁺ formation channel and H⁺ formation channel show a significant yield changes, producing the highest and lowest at ellipticity of 0.59 respectively. With the help of theoretical calculations, we attribute such a control to both angle dependent ionization and intensity dependent ionization to excited dication states.