Abstract
The lasing threshold of evanescent-wave pumped whispering_gallery_mode （WGM） fiber lasers has been studied. Quartz fibers of different diameters were immersed in a mixed solution of ethanol and ethylene glycol doped by rhodamine 6G dye molecules, the refractive index of the solution was variable and lower than that of quartz fiber. We find that the dependence of lasing threshold on the refractive index of the mixed solution differs for different diameter of quartz fiber. With the increase of refractive index of the mixed solution from 1362 to 1432, the threshold energy decreases slowly and monotonicly for fibers of diameters larger than 296 μm, but increases for fibers of diameters smaller than 93 μm; for a fiber of diameter 197 μm, the threshold energy decreases slowly at first, and then increases sharply, there is an optimum refractive index of the mixed solution which matches a minimum threshold energy. Based on the theory of evanescent-wave pumped WGM fiber laser, we deduce a formula of lasing threshold, the calculated curves of lasing threshold are well consistent with the experimental data.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
