Random lasing in freely suspended dye-doped nematic liquid crystals.
Random lasing in fully disordered systems having organic and inorganic nature has been the subject of extensive studies since the beginning of the past decade. The interest mainly emerges from the unexpected role played by disorder in the laser action. The disorder was considered detrimental for the optical feedback in cavity laser, until it was demonstrated that multiple-scattering materials including a gain medium act as random laser. Here, a completely new approach is reported, where freely suspended complex fluid films doped with fluorescent molecules under optical excitation generate narrowband lasing peaks. The constellation of localized modes is selected by properly choosing the gain profile. The idea to have laser action in absence of mirrors and boundaries realizes an unparalleled tunable and moldable laser source.
Ferjani
Sameh
S
Licryl CNR-INFM and CEMIF. Cal Center of Excellence Innovative Materials for Photonics, Department of Physics,University of Calabria, I-87036 Rende CS, Italy.
Barna
Valentin
V
De Luca
Antonio
A
Versace
Carlo
C
Strangi
Giuseppe
G