Cylindrical microcavity structures, such as microrings and microdisks of pi
-conjugated conducting polymers were fabricated for an optically pumped las
er and a light, emitting diode (LED). Extremely low excitation threshold fo
r lasing has been demonstrated with the microring or microdisk structure. M
icro-LEDs with cylindrical geometry of Al/pi-conjugated conducting polymers
/ITO have been fabricated and the electroluminescence has been observed upo
n application of an electric field. These results suggest the future possib
ility of electrically pumped conducting polymer laser diodes.