Microsphere-coupled organic waveguides: Preparation, remote excitation of whispering gallery modes and waveguiding property

Abstract

In this letter, we show how organic molecular waveguides of 1,5-diaminoanthraquinone molecules can be grown on a silica microsphere to obtain microsphere-coupled organic waveguides (MOWs). Using such MOWs, we remotely excite and detect whispering gallery modes (WGMs) of the attached microsphere. Interestingly, these WGMs showed mode-splitting and mode-mixing due to broken azimuthal symmetry of the microsphere. Furthermore, the waveguiding characteristics of MOWs showed a quadrupole intensity pattern as a function of input polarization. The presented geometry can be an excellent test-bed to study fundamental aspects of coupled resonant systems, and their properties can be harnessed in nano- and bio-photonics.