Photon avalanche effect in quantum wells: controlling light with light
A. A. Popov, Andrei V. Ivanov, E. Yu. Perlin · Journal of the Optical Society of America B · 2019
A new mechanism of controlling the absorption of high-intensity signal light with frequency $\omega $ω and intensity ${j_\omega }$jω by complementary control light with frequency $\Omega \gt {2}\omega $Ω>2ω and 2 or 3 orders of magnitude lower intensity ${j_\Omega }$jΩ is proposed. The mechanism is based on the photon avalanche effect in quantum wells. The electron concentrations in size-quantization subbands and conduction band continuum and the absorbed power of signal light are obtained as functions of the intensities ${j_\omega }$jω and ${j_\Omega }$jΩ and the time of exposure to laser radiation $t$t. It is established that the resulting dependences exhibit well-pronounced threshold behavior. For example, at ${j_\Omega }\;\sim\;{0.2 - 1}\;{\text{kW/cm}^2}$jΩ∼0.2−1kW/cm2 and $t\;\sim\;{0.1 - 5}\;\text{ns}$t∼0.1−5ns, it is possible to control the absorption of signal light, so that the absorption of this light is practically lacking at intensities ${j_\omega }$jω below the threshold intensity (${40 - 200}\;{\text{kW/cm}^2}$40−200kW/cm2) and becomes very strong at intensities above the threshold intensity. The case when control light $\Omega $Ω is the third harmonic of high-intensity signal light is also considered.