Waveguiding-assisted random lasing in epitaxial ZnO thin film

P.-H. Dupont (1) , Christophe Couteau (1) , D. J. Rogers (2) , F. Hosseini Teherani (2) , Gilles Lerondel (1)

1 LNIO - Laboratoire de Nanotechnologie et d'Instrumentation Optique
2 Nanovation SARL

Zinc oxide thin films were grown on c-sapphire substrates using pulsed laser deposition. Pump power dependence of surface emission spectra, acquired using a quadrupled 266 nm laser, revealed room temperature stimulated emission (threshold of 900 kW/cm2). Time dependent spectral analysis plus gain measurements of single-shot, side-emission spectra pumped with a nitrogen laser revealed random lasing indicative of the presence of self-forming laser cavities. It is suggested that random lasing in an epitaxial system rather than a three-dimensional configuration of disordered scattering elements was due to waveguiding in the film. Waveguiding causes light to be amplified within randomly formed closed-loops acting as lasing cavities.

Keywords: Emission spectroscopy; Pulsed laser deposition; Excitons; Laser resonators; Epitaxy; Semiconductor device fabrication; Laser theory; Thin films; Optical properties; Optical resonators

Domains: Optics [physics.optics]

P.-H. Dupont, Christophe Couteau, D. J. Rogers, F. Hosseini Teherani, Gilles Lerondel. Waveguiding-assisted random lasing in epitaxial ZnO thin film. Applied Physics Letters, 2010, 97 (26), pp.261109. ⟨10.1063/1.3527087⟩. ⟨hal-02473076⟩