We report on random lasing in substituted quinquethienyl S,S-dioxide neat films. Despite the absence of highly efficient scatterers in the film, a fine structure with laser-like peaks as narrow as 5 Å is observed in the emission spectra. The far-field emission pattern is studied through angle-resolved emission measurements, demonstrating that random lasing emission is directional, with a 8° divergence but different individual emission patterns. The origin of the scattering centers providing the feedback for lasing has been analyzed through atomic force microscopy measurements of the film surface. We demonstrate that the random lasing is induced by sequential scattering from 50 nm diameter holes in the film with an average distance of 500 nm, while thickness fluctuations are not relevant.

Far-field emission and feedback origin of random lasing in oligothiophene dioxide neat films

ANNI, Marco;LATTANTE, SANDRO;GIGLI, Giuseppe;CINGOLANI, Roberto
2003

Abstract

We report on random lasing in substituted quinquethienyl S,S-dioxide neat films. Despite the absence of highly efficient scatterers in the film, a fine structure with laser-like peaks as narrow as 5 Å is observed in the emission spectra. The far-field emission pattern is studied through angle-resolved emission measurements, demonstrating that random lasing emission is directional, with a 8° divergence but different individual emission patterns. The origin of the scattering centers providing the feedback for lasing has been analyzed through atomic force microscopy measurements of the film surface. We demonstrate that the random lasing is induced by sequential scattering from 50 nm diameter holes in the film with an average distance of 500 nm, while thickness fluctuations are not relevant.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11587/108959
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact