Evanescent-wave-excited quasi-two-dimensional random lasing.
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.
Mujumdar
Sushil
S
Raman Research Institute, C.V. Raman Ave., Sadashivnagar, Banglaore, India.
Ramachandran
Hema
H
Kumar
N
N
Sood
A K
AK