We study the transport of optical waves through media which have a variation in the refractive index over length-scales comparable to the wavelength. These experiments deal with visible or near-infrared radiation. The structure can be ordered, disordered or even a combination of both. Given that light can experience amplification and nonlinear effects, fascinating phenomena, hitherto unpredicted by theory, are unravelled in thesesystems. Sophisticated laser sources, ultrasensitive detectors, and nanofabrication techniques makes it possible to observe even the most elusive of phenomena!
Anderson localization: A most exotic optical phenomenon, realized by disorder-inducedinterferences, directly observed in the lab.