Developments of Random Laser: Fundamentals and Applications

The development of laser in the twentieth century is one of the important milestones in the field of science and technology having enormous impact on technological innovations. And quite interestingly, a different type of laser device, namely random laser can be engineered by manipulating walk of photons inside a disorder system. However, in this chapter, a mini review on different fundamental theoretical backgrounds of random laser and its photonics applications have been presented. Also, techniques for tuning random laser emission characteristic in continuous and pulsed regime are outlined. Role of external feedback on reducing pump threshold and improving statistical behavior of random laser emission from ZnO microcabbage and DCM dye dopped polymer film is reviewed based on some recent reports. Thereafter, speckle free imaging application using ZnO based external feedback random laser device has been revisited. Additionally, techniques of generation of random laser emission using nature inspired scatterers and gain molecules are reviewed. In this regard, random laser emission from dye loaded bamboo leaves, chlorophyll and bio-dye extracted from Clitoria ternatea flower is highlighted. This chapter may provide a roadmap for sustainable development of random laser devices for robust photonic applications in future.