Effect of cyclooctatetraene on the laser properties of rhodamine 6G solution under flashlamp excitation

The metastable level lifetime of rhodamine 6G in ethanol solution was measured by a dye laser with and without a cyclooctatetraene additive. In contrast to the existing ideas it was shown that the presence of cyclooctatetraene not only fails to decrease but on the contrary increases the lifetime τ_T of this dye. The improvement observed in the oscillation properties is expected to be connected with the decrease of the interconversion rate in a rhodamine 6G molecule when it is surrounded by a shell of the cyclooctatetraene molecules.