Fig. 1. Schematic diagram of the quantum well based on micropillar array

Fig. 2. Simulated reflectivity of the micropillar arrays with different dimensions

Fig. 3. Enhanced absorption effect of quantum well micropillar arrays (D = 2.2 μm, P = 4 μm, H = 4 μm) at λ = 8.7 μm (a) Imaginary part of the permittivity in the z direction (Im (ε_z) ) of quantum well vary with wavelength, (b) Simulated absorption spectrum of micropillar array and 45°edge facet, (c) Simulated E_z distribution for D = 2.2 μm, P = 4 μm, H = 4 μm on the x-z plane, (d) Simulated E_z distribution on the x-y plane at z = 1.6 μm

Fig. 4. Process of quantum well micropillar arrays

Fig. 5. Images of GaAs/AlGaAs quantum well based micropillar arrays and diffraction pattern of lithography (a) SEM image, (b) AFM section image, (c) diffraction pattern of lithography process on x-z plane, (d) diffraction pattern of lithography process on x-y plane at z = 1.0 μm

Fig. 6. Reflectance spectrum of micropillar arrays at different periods and diameters