A random laser is a laser that uses a highly disordered gain medium. A random laser uses no optical cavity but the remaining principles of operation remain the same as for a conventional laser. Random laser action has been observed in many different media, including semiconductor powder, nanostructured and non-nanostructured thin films, laser dyes, ceramics and many more.Developments in nanoparticles have demonstrated that large amounts of optical scattering can occur when photons are incident.