The Perylene Derivative BASF-241 Solution as a New Tunable Dye Laser in the Visible

Some basic optical properties of the perylene derivative BASF-241 solution in chloroform, relevant to its application as a dye laser, were measured. The fluorescence spectrum, excited by frequency-doubled (532 nm) Nd:YAG laser pulses, shows three pronounced peaks centered at 540, 580, and 630 nm, with a Stokes shift and mirror image in relation to the absorption spectrum. The quantum yield was about a unity, with a lifetime of 5.0 ± 0.5 ns. Addition of trichloroacetic acid (CCl3COOH) causes a red shift of absorption and fluorescence spectra by about 750 cm-1 - L/mol. In a cavity consisting of a -100% reflecting back mirror and an 8% reflecting output coupler, lasing was obtained at 577 nm, with a threshold of ~10 μj/ pulse, and a slope efficiency of about 8%. Medium losses were attributed to excited singlet-singlet absorption of cross section 1–2. 10-16 cm2. Using a grating, a tuning range of almost 20 nm was obtained, centered at the 0–1 fluorescence emission peak. The laser range shifted to the red when the dye was dissolved in chloroform with an increasing concentration of trichloroacetic acid. The BASF-241 solution in chloroform thus appears to be a new, promising material for a dye laser.