Figure 3: Propagation and cascadability.
(a) Scheme of the experimental configuration with two Address beams focused in separated points of the sample with different incident angles. (b) Scheme of the polariton propagation when the Control C is focused over Address A, with the red arrows indicating the propagation direction of the respective polariton states. (c) Real space image of the emission intensities of the Address A and B, and of the Control C below threshold. Scale bar, 25 μm. (d) Far field image of the emission intensities showing the momenta of A, B and C. The circle corresponds to the position of the elastic scattering ring. (e) Real space image of the propagating states A and B, above threshold thanks to the small increase of the intensity of C (same powers as in Fig. 2). Note that the intensity in panel (c) has been multiplied 20 times in order to get the same colour scale as in panel (e). Scale bar, 25 μm. (f) In momentum space, A and B are now on resonance with the laser energy and their intensities increase abruptly, while the intensity of C is negligible. (g) Emission intensity profile along the horizontal direction and graphic representation of the gain G.
