Dispersion and lasing in excitonic media

We studied reflection and dispersion in Rhodamine laser dyes in the Kretschmann geometry and found (i) multi-branch “staircase” dispersion curves in singly doped and double doped PMMA polymer, (ii) emergence of the new dispersion “fork” branch. We further studied spontaneous, stimulated and polaritonic emission of Rhodamine laser dyes and found (iii) anomalous Anti-Stokes shift of spontaneous and stimulated emission bands as well as (iv) effect of the strong coupling on the Foerster energy transfer.