Reduction in lasing threshold of hollow-core microstructured optical fiber optofluidic laser based on fluorescence resonant energy transfer

Abstract We demonstrate an optofluidic microcavity laser based on a hollow-core microstructured optical fiber (HCMOF), which uses the hexagonal silica membrane embedded in the HCMOF as resonator. Fluorescence resonant energy transfer (FRET) effect is introduced into the laser successfully when mixed anthocyanin dye solution is used as gain medium. The threshold of the laser is systematically investigated for several concentration proportions of donor dye to acceptor dye. The results prove that the FRET-based laser shows a considerable reduction in lasing threshold from 595 nJ/mm2 to 113 nJ/mm2. The effect of FRET on lasing threshold makes this HCMOF-based optofluidic microcavity laser to be a promising candidate for biochemical sensing applications.