Investigation of spontaneous emission dynamics of dye molecules coupled into transverse Anderson localized cavities in a hyperbolic waveguide

•Spontaneous emission of dye molecules coupled into multimode transverse Anderson localized modes in a hyperbolic waveguide is investigated.•Physics behind the transduction mechanism is explained with the coupling of the emitter emission into transverse Anderson localized modes.•Photonics design of the cavity allows generation of multimode Anderson localized modes.•A naturally formed disordered photonic medium in a simple hyperbolic waveguide is demonstrated to enhance light-matter interaction. Spontaneous emission dynamics of rhodamine 6G molecules coupled into transverse Anderson localized modes in a hyperbolic waveguide is investigated using time-resolved experiments. Four hyperbolic waveguides are simultaneously formed inside a deltoid-shaped fused-silica microtube via the capillary effect. The disordered photonic environment consisting of a rhodamine-doped polymeric material with randomly distributed air inclusions is attributed to localize photons at various resonant wavelengths of the quasi-optical cavities, randomly positioned throughout the guiding medium. The hyperbolic waveguides allow obtaining a single, double, and multimode resonant structures, trapping photons at various frequencies as explored in the form of sharp spectral resonances within the photoluminescence spectrum bandwidth of the dye molecules. Experimental results reveal that the coupling of the fluorescent emitters into multimode localizations in each hyperbolic waveguide corresponds to obtaining quasi-optical cavities at various resonant frequencies, which alter the emission characteristics of the emitters distinctively. The spontaneous emission rate of the dye molecules coupled into the isolated transverse Anderson localized modes is observed to increase by a factor of up to 6.7; thus, the vacuum fluctuations at certain resonant wavelengths are considerably enhanced.