Microfiber knot dye laser based on the evanescent-wave-coupled gain Available to Purchase

The authors demonstrate a composite microring laser formed by immersing a silica microfiber knot in a rhodamine 6G dye solution. When the dye molecules are evanescently pumped by $532nm$ wavelength laser pulses guided along a $350μm$ diameter knot, lasing oscillation occurs inside the evanescently coupled closed-ring microcavity with a linewidth of about $0.06nm$⁠. Laser emission around 570 and $580nm$ wavelengths, which is evanescently coupled back into the microfiber, is observed with a threshold of about $9.2μJ∕pulse$⁠. The use of the microfiber knot cavity suggests a convenient and efficient approach to both pumping and collection of the evanescent-wave-coupled dye laser.