Modified light emission from emitters coupled to long-range guided modes in strongly absorbing layers

We demonstrate the near-field coupling and energy transfer between photoexcited dye molecules and guided modes in layers of strongly absorbing dielectrics. The dye molecules decay by exciting long-range guided modes (LRGMs) in a thin layer of chalcogenide glass. These modes can exist in spite of the very large absorption of the material forming the layer. The LRGMs are detected by coupling then out to free space radiation through a prism in the Krestschmann configuration. By calculating the dissipated power of a dipole, representing a dye molecule, in the vicinity of the absorbing thin film, we show that there is a large probability of decay exciting LRGMs. This probability can reach 35% for perpendicularly oriented dipoles. The demonstration of the excitation of LRGMs in thin films of absorbing dielectrics by near-field coupling of excited molecules opens the possibility to compensate for the losses in the propagation of these modes.