Whispering gallery modes of dye-doped polymer microspheres in microtube

摘要

A micro-system including a silica micro-tube (inner diameter approximate to 6.2 mu m) and dye-doped microspheres (diameter approximate to 6 mu m) was pumped by a 532 nm laser. The whispering gallery modes (WGMs) of fluorescence resonance were observed. Free Spectral Range (FSR) of single-sphere with diameters of 40 mu m was 3.1 nm and with diameters of 6 mu m was 5.4 nm. Two size-matched microspheres were coupled using a bi-sphere micro-system. Resonances from each sphere's evanescent field were coupled, which leads to resonance splitting. The measured resonance splitting in the spectra of the two coupled spheres is about Delta lambda approximate to 0.8 nm. The scheme would be a promising component in future micro-photonic devices. (C) 2015 Elsevier B.V. All rights reserved