Study On Waveguiding Characteristics Of 3,3'-dithylthiacyanine Nanowires

With the miniaturization of optoelectronic devices,optical waveguides in the order of microns or even nanometers will become an important part of the photonic circuit.However,the optical diffraction limit greatly hinders the progress of miniaturization of the conventional optical waveguide.In recent years,plasmon waveguides,photonic crystal waveguides,and semiconductor nanowire waveguides have been found to efficiently transmit optical signals at the diffraction limit.Among them,organic semiconductor nanowires form exciton polaritons by strong coupling between photons and excitons in their interiors,and propagate photons in the form of exciton polarons.This special transmission mechanism makes it a current research.Hot spot.In recent years,it has been found that 3,3'-dithylthiacyanine(TC)nanowires prepared from TC dye molecules can propagate fluorescence along the axis of the nanowires to achieve the role of active optical waveguides.Firstly,we apply the self-assembly effect of organic molecules to prepare TC organic polymer nanowires with smooth surface and uniform thickness,and realize the controllable preparation of nanowires by changing the preparation conditions,such as the growth period and solution concentration.The absorption spectra of the prepared TC nanowire solution and the TC monomer solution were compared to determine that the aggregation type of the TC nanowires was H aggregate.Secondly,the internal energy level structure of TC nanowires was analyzed by fluorescence spectra of TC monomer films and TC nanowires.The fluorescence lifetime curves and kinetic curves of TC nanowires were studied and the formation process of exciton polaritons was found.In addition,the number of optical modes transmitted within the TC nanowires and their cut-off wavelength were obtained by theoretical calculations.The non-local fluorescence spectra of the TC nanowires were detected and the transmission band and transmission loss of the TC nanowires were studied.Finally,the waveguide mode conversion of TC nanowires is realized under different substrate and different excitation conditions.