title: Evanescent-wave-excited quasi-two-dimensional random lasing.
abstract: We report on random lasing from a dye-scatterer system directly excited by evanescent modes formed over a dielectric-dielectric interface. The system is quasi-two-dimensional because of the subwavelength exponential decay of the excitation energy. Spectral narrowing by a factor of approximately 13 was obtained under diffusive scattering conditions. The peak intensity exhibited a unique dual-saturation behavior due to the localized nature of the excitation. We observed a reduction of threshold for samples with a higher dye concentration because of a larger excitation-state occupation number within the same interaction volume.
authors.affiliation: Raman Research Institute, C.V. Raman Ave., Sadashivnagar, Banglaore, India.
authors.forename: Sushil
authors.initials: S
authors.lastname: Mujumdar
authors.forename: Hema
authors.initials: H
authors.lastname: Ramachandran
authors.forename: N
authors.initials: N
authors.lastname: Kumar
authors.forename: A K
authors.initials: AK
authors.lastname: Sood