Lasing action of active-particles dispersed in microdroplets and its enhanced characteristics by highly scattering intralipid-10% mixture

The first laser action of active-particles of 1-2 mu m in diameter, red flu orescent-powder (FP), dispersed in nonactive (nonlasing) similar to 100 mu m-sized liquid microdroplets is reported. Lasing characteristics of FP-cont aining microdroplets by mixing Intralipid-10% as highly scattering turbid m edia are also described. Well-defined lasing thresholds can be confirmed fr om the FP-dispersed pure microdroplets, and lowered lasing threshold along with enhanced lasing emission is achieved by appropriately mixing the Intra lipid-10% solution. Lasing threshold in these microdroplets can be determin ed not through the spectral narrowing features but through the input-output data. We believe that these new microdroplet configurations offer one of t he new categories of lasing media and they seem also to simulate to some bi ological pigments or organelles contained in cells and small tissues.