ABSTRACT
Unlike a conventional laser, which utilizes mirrors or periodic
structures to trap light, a random laser relies on the multiple
scattering of light in a disordered gain medium for optical feedback
and light confinement [1-4] (Fig. 4.1). Coherent laser emission
has been generated from various random structures ranging
from semiconductor nanopartricles and nanorods to polymers
and organic materials. Over the past decade, random lasers have
generated significant interest among researchers because of their
unique applications [3, 4] based upon the spectral fingerprint of the
random structure, theirmicron size, low fabrication cost, robustness
to surface roughness and shape deformation, and nearly isotropic
emission output. These characteristics are ideal for identification,
encoding, tagging, and optical sensing.
