Fig. 2: Photoluminescence (PL) characterisation. | Nature Communications

Fig. 2: Photoluminescence (PL) characterisation.

From: Ultrafast-nonlinear ultraviolet pulse modulation in an AlInGaN polariton waveguide operating up to room temperature

Fig. 2: Photoluminescence (PL) characterisation.The alternative text for this image may have been generated using AI.

a PL spectra emitted inside the light cone (near zero in-plane momentum) showing exciton and buffer layer emission for various temperatures. Curves are vertically offset for visibility and plotted on a logarithmic scale. CW denotes continuous-wave excitation. b Polariton PL spectra after propagating 50 μm from the excitation spot to the gratings (see Fig. 1b). Vertical black dashed lines are at the QW A exciton frequency and 35 meV and 92 meV below the A exciton frequency. c, d Angle-resolved polariton PL spectra at temperatures T = 4 K (b) and T = 300 K (c). The solid white curves (LPB1 and LPB2) denote the best fit forward and backward propagating lower polariton branches. The dashed white curves (Γ) give the calculated uncoupled photon dispersion. The dashed vertical line (X) denotes the exciton frequency. The exciton emission has been subtracted to highlight the polariton modes (see ‘Methods’).

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