Waveguide mode lasing via evanescent-wave-coupled gain from a thin cylindrical shell resonator

We reported waveguide mode lasing in a thin dielectric cylindrical shell made on the inner wall of a circular capillary, in which the laser oscillation was achieved through the evanescent-wave-coupled gain from the interior dye-doped liquid. Periodically peaked spectra of waveguide modes showed blueshift when the refractive index of interior liquid was decreased. We could quantitatively estimate the occupation factor of inner evanescent-wave portion from the dependence of blueshift, which allowed the spectral analysis on the effective cavity quality factor Q. Typical Q of the lasing waveguide modes was about 2x10(6). (C) 2004 American Institute of Physics.