Pattern formation under bistable electro-optical absorption in quantum wells: I

We have formulated and analysed a model of transverse self-sustained pattern formation in a photoexcited and voltage-biased quantum well (QW) structure. Our model explains the formation of patterns of quasi-neutral two-dimensional electron-hole plasma whose intrinsic bistability was shown in recent experiments. A number of patterns containing regions with different spreading of the electron and hole wave functions and different densities of the two-dimensional electron-hole plasma have been found by using a nonlinear interband light-absorption model. When the transverse extent of the QW layer is large in comparison with the pattern characteristic transverse length scale (of the order of the two-dimensional plasma ambipolar diffusion length), most patterns consist of wide plateaus with high (low) plasma density and relatively narrow domains with low (high) density.