WHISPERING-GALLERY-MODE MICRORING LASER USING A CONJUGATED POLYMER

We observed laser emission in whispering gallery modes using a microri ng composed of a semiconducting polymer oly[2,5-bis-(2'-ethylhexyloxy) -p-phenylenevinylene coated on an etched fiber under transient and qua sisteady-state pumping conditions. The threshold for laser oscillation was 1 mJ/cm(2) (0.1 MW/cm(2)) and 30 mu J/cm(2) (300 MW/cm(2)) for na nosecond and femtosecond excitation, respectively. The laser output sh owed superlinear dependence on the excitation energy above the thresho ld, The demonstration of lasing under quasisteady-state pumping shows the possibility to develop electrically pumped polymer lasers, (C) 199 8 American Institute of Physics.