Multiphasic nanostructured composite: Multi-dye tunable solid state laser

In this paper we present a new concept to control the energy transfer between two components using novel multiphasic nanostructured composites. The example studied here consists of two lasing dyes (Rhodamine 6G and trans-4-[p-(N-ethyl-N-(hydroxyethyl)amino)phenylstyryl]-N- (hydroxyethyl)pyridinium iodide (ASPI), each of which resides in two different phases of a multiphasic composite. The energy transfer between these two phases was studied and found to be insignificant. Therefore, this composite exhibited lasing from both dyes. The multiphasic matrix was tunable through the range of both dyes from 560 to 610 nm with an efficiency of nearly 7%. The lasing properties of this lasing media were studied compared to reference dye solutions. In the solution state a mixture dye solution exhibited complete quenching of one of the dyes (Rhodamine-6G). The quenching mechanism in the solution state and its lack in the solid state matrix is proposed. In addition, the new laser dye, ASPI, has been characterized by its linear spectroscopy and lasing properties in solution. The results of this characterization reveal a dye with a low fluorescence quantum yield (nearly 7 × 10^-3), but high lasing efficiency (nearly 13.5%) under pulsed pumping conditions. As intersystem crossing from the S₁ to T₁ state may be responsible for this phenomenon.