Naturally occurring resonators in random lasing of π-conjugated polymer films

Random nanolasing in the Anderson localized regime

“…Figure 3b presents the distribution of lasing thresholds observed experimentally. An asymmetric threshold distribution with a long tail extending to high threshold values is obtained, as predicted by theory 28 , in contrast to the symmetric threshold distributions observed for diffusive random lasers 29 . The average threshold of 418 mW is comparable to the typical threshold of standard photonic-crystal lasers pumped in a similar geometry 23,30 and is 20 times lower than the threshold measured for a macroscopically structured one-dimensional disordered medium in the localized regime 17 .…”

Lévy Statistics and Glassy Behavior of Light in Random Fiber Lasers

“…That report was followed by a great number of papers from different authors that investigated on other physical systems for efficient RL operation. A large variety of materials has been tested in the past years, and recent publications on RLs describe, for example, experiments with dyes dissolved in transparent liquids, gels or liquid crystals with suspended micro or nanoparticles as light scatterers [12][13][14][15][16][17], powders of semiconductor quantum dots [18,19], dielectric nanocrystals doped with rare-earth ions [20,21], polymers and organic membranes doped by luminescent molecules [22][23][24][25][26][27], semiconductor and metallic nanowires structures [28][29][30][31], and even atomic vapors that present analogies with astrophysical lasers [32].…”

Perspectives: Nanofibers and nanowires for disordered photonics

“…Systems which can be useful in this respect include clusters of nanoparticles, inorganic semiconductor powders, colloids, polymers, biological tissues, aerosols of microdroplets, and porous glasses. [2][3][4][5][6][7][8] Important aspects which affect the behaviour of light in these systems are the elastic character of diffusion and the possibility of interference which is not lost even after multiple scattering events, since the phase of optical wavelets is kept well-defined. In this way, many disordered materials are able to provide coherent feedback for light, which, combined with sufficient optical gain given by stimulated emission from some part of the system, is what is needed for achieving lasing.…”

“…The active medium providing gain can be either inorganic 2,3 or organic. 5,6 Since an external cavity is missing, random architectures might greatly simplify the realization and reduce the cost of laser devices, especially for applications where low coherence might be desired, such as for speckle-free imaging. 10 Other target fields for random lasers include chemical and biological sensors, and medical diagnostics.…”