Understanding and control of random lasing

Random lasing attracts much attention because it helps to understand coherent phenomena in disordered media and can be used in optoelectronics due to easy preparation (no need in mirrors) and small size of random lasers down to few microns. Recently the remarkable progress in studying the material, geometry and external pumping dependences of laser properties and efficiency has been reached. Lasing emerges from the special random cavities of high quality formed within the active medium. They can be described as the decaying eigenoptical modes within the medium and the optical mode having the minimum decay rate is responsible for lasing. Numerical and analytical studies of the properties of these modes permit to interpret existing experiments and suggest the ways to optimize the performance of lasers. (C) 2003 Elsevier B.V. All rights reserved.