This paper presents the characteristics of energy transfer distributed feedback dye laser (ETDFDL) in a
mixture of Rhodamine B (RhB) and Thionine (Th) dyes pumped by 532 nm Nd:YAG laser both theoretically and
experimentally. The characteristics of donor DFDL, the acceptor DFDL, the dependence of their pulse widths and
output powers on donor-acceptor concentrations and pump power are studied. Experimentally the output energy of
DFDL is measured at the emission peaks of donor and acceptor dyes for different pump powers, donor-acceptor
concentrations and the tunability is observed from 565 nm to 665 nm using prism dye cell arrangement.
In this paper, a simple method of pulse narrowing by double Q-switching is presented. In energy transfer distributed feedback dye laser (ETDFDL) when acceptor dye acts as a saturable absorber, pulse narrowing is observed in both donor and acceptor emission regions. In prism-dye cell configuration using second harmonic of Nd-YAG laser as pump source, the ETDFDL output is obtained from dyes Rhodamine 6G (R6G) as donor and Acid Blue 7 (Ab7)/Thionine (Th) as acceptors. In Rhodamine 6G and Acid Blue 7 combination pulse narrowing is observed only in the acceptor region whereas in the other combination namely Rhodamine 6G and Thionine, it is observed in both donor and acceptor regions. This is because of good overlap of the emission spectra of donor with the absorption spectra of acceptor. The detailed study is presented in this paper.