RING MICROLASERS FROM CONDUCTING POLYMERS

We demonstrate pulsed, photopumped multimode laser emission in the visible spectral range from cylindrical microcavities formed by conducting polymer thin films deposited around optical fibers. The laser is characterized by narrow emission lines ({approximately}1.5cm{sup {minus}1}), a well-defined excitation threshold, anisotropic emission in both polarization and azimuthal intensity distribution, and high Q({ge}3000), which leads to a low excitation threshold of order 1 nJ/pulse. We observed two different sets of laser modes; these are waveguided ring modes in the polymer film and whispering gallery modes close to the optical fiber surface. {copyright} {ital 1997} {ital The American Physical Society}