Strong localization and suppression of Anderson modes in an asymmetrical optical waveguide

In this paper, transverse Anderson localization of light waves in a 3D random network is achieved inside an asymmetrical type optical waveguide, formed within a fused-silica fiber by capillary process. Scattering waveguide medium originates from naturally formed air inclusions and Ag nanoparticles in rhodamine dye doped-phenol solution. Multimode photon localization is controlled by changing the degree of the disorder in the optical waveguide to suppress unwanted extra modes and obtain only one targeted strongly localized single optical mode confinement at the desired emission wavelength of the dye molecules. Additionally, the fluorescence dynamics of the dye molecules coupled into the Anderson localized modes in the disordered optical media are analyzed through time resolved experiments based on a single photon counting technique. The radiative decay rate of the dye molecules is observed to be enhanced up to a factor of about 10.1 through coupling into the specific Anderson localized cavity within the optical waveguide, providing a milestone for investigation of transverse Anderson localization of light waves in 3D disordered media to manipulate light-matter interaction.