Coherent backscattering from high-gain scattering media

Dynamics of random laser and coherent backscattering of light from ZnO amplifying random medium

“…This phenomenon of an enhanced backscattering cone was also observed in other active media, such as Ti:sapphire powder and a dyeparticle mixture under a weak scattering regime, and its behavior above and below the laser threshold is also similar. 9,10 In particular, we did not observe a runaway growth of the backscattering cone above the laser's threshold, probably due to ultrafast population decay above the laser threshold. 11 We must also emphasize that the sharp peak seen at the center of the backscattering cone at zero delay is not an artifact such as a speckle effect.…”

“…The angular width of the backscattering cone can then be used to determine whether the scattering process is in the strong or weak localization regimes. 8 Although coherent backscattering has been measured in amplified random media, [9][10][11] the systems studied were only in the weakly scattered regime.…”

Dynamic Coherent Backscattering Mirror

“…[30][31][32] CBM may find applications in real time correction of dynamic phase distortions (aberrations) in passive and active optical components such as correcting phase distortions in a multi-pass amplifying system. The CBM enhancement profile can be used to conveniently quantify local optical properties of a random medium in biomedical applications and remote sensing in general.…”

Dynamics of a Random Laser above Threshold

“…Earlier EBS experiments [8,9] were performed with materials in which the laser threshold could not be reached. In our sample the laser threshold is found to be at a pump fluence of 10 mJ͞mm 2 from the width of the fluorescence spectrum as a function of the pump pulse energy.…”