Dye lasers using tapered optical fibers.

A new type of dye laser operating in a single-mode optical fiber has been studied. The gain is produced by surrounding a tapered section of the fiber with laser dye. Interaction of the light in the fiber with the laser dye is achieved through the exposed evanescent field at the taper waist. Low lasing thresholds (25-65 mW) are obtained as a result of the high intensities at the taper waist. These tapered fiber dye lasers combine the advantages of a laser in fiber form with the wide spectral tuning ranges provided by laser dyes. Three experiments, demonstrating low-threshold operation of a grating tuned laser, an all-fiber ring laser, and cw lasing in tapered fiber dye devices, are presented.