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arXiv · 1407.7376

Transition from non-resonant to resonant random lasers by the geometrical confinement of disorder

N. Ghofraniha·I. Viola·A. Zacheo·V. Arima·G. Gigli·C. Conti
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Abstract

We report on a novel kind of transition in random lasers induced by the geometrical confinement of the emitting material. Different dye doped paper devices with controlled geometry are fabricated by soft-lithography and show two distinguished behaviors in the stimulated emission: in the absence of boundary constraints the energy threshold decreases for larger laser volumes showing the typical trend of diffusive {\it non-resonant} random lasers, while when the same material in lithographed into channels, the walls act as cavity and the {\it resonant} behavior typical of standard lasers is observed. The experimental results are consistent with the general theories of random and standard lasers and a clear phase diagram of the transition is reported.

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N. Ghofraniha, I. Viola, A. Zacheo, V. Arima, G. Gigli, C. Conti. 2014-07-28. Transition from non-resonant to resonant random lasers by the geometrical confinement of disorder. https://doi.org/10.1364/ol.38.005043

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