Spectral characteristics of single and coupled microresonator lasers comprising a replica-molded Bragg grating and dye-doped polymer

Visible microlasers consisting of 80 ± 20 nm thick, dye-doped polymer resonators mated to a second-order, distributed feedback grating having a period of 410nm exhibit longitudinal mode and spectral characteristics that can be manipulated by microresonator design. Resonators in the form of a square, ring (annulus), or a ring with an intentionally introduced defect (π/2 section removed) have been examined with respect to the output spectrum, pump energy threshold, and relative slope efficiency of the corresponding microlaser. Although the emission of single rings and arrays of nonoverlapped rings is generally a single mode, the square geometry resonator exhibits a spectrum rich in mode structure, which is attributed partially to degeneracies associated with two coupled Fabry- Perot resonators. Similarly, arrays of coupled (overlapped) rings produce multimode spectra that are skewed toward the blue. For a fixed pump fluence, an array of coupled rings generates output energies at least 50% higher than those for its uncoupled counterpart.