Nowadays, there are many ideas for the realization of distributed feedback (DFB) lasers in either a mono- and bilayer system with a permanent or temporary holographic pattern. Because feedback in DFB lasers can be provided by gain and/or refractive index periodic perturbations, there may be several approaches to their realization, however, dynamic tuning is limited. In our studies we show that using simple systems based on a single organic dye-doped polymeric thin films for distributed feedback, we can get fully reversible spectral tuning of 150 nm. As active compounds we have applied novel push-pull luminescent pyrazoline, diphenylaminofluorene and thiophene derivatives, with different acceptor groups. Integration of such luminescent dyes with transparent polymeric medium allows fabricating real-time lasing tunability in the visible region and first biological window (650-950 nm). Also Excited-State Intramolecular Proton Transfer (ESIPT) compounds, have attracted our considerable attention. Such structure enabled real-time red-green-blue (RGB) switching of emission, both in solution and solid-state, providing white laser light emission.
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