LOW-THRESHOLD LASING OF A RHODAMINE DYE SOLUTION EMBEDDED WITH NANOPARTICLE FRACTAL AGGREGATES

The spectral and temporal emission properties of a Rhodamine (Rh) dye solution embedded with nanoparticle fractal aggregates are studied. An experiment on the pump-power density dependence of Rh emission spectr a shows that the lasing threshold of a Rh6G solution embedded with TiO 2 nanoparticle fractal aggregates is significantly reduced compared wi th that of a neat dye solution. The mechanism of this reduction in las ing threshold is discussed, together with the lasing properties of nar row bandwidth and short duration. (C) 1998 Optical Society of America.