Polarization inversion via parametric scattering in quasi-one-dimensional microcavities

Parametric polariton scattering is studied in quasi-one-dimensional microcavities. A polarization splitting of the polariton modes is observed and its origin is discussed. In contrast to planar cavities, here, the large splitting leads to a comprehensive analysis of the polarization dynamics. We demonstrate phase matched intersubbranch parametric polariton scattering at $k=0$ with an inversion of the linear polarization of signal and idler with respect to the pump beam.

Figure 1

(a) Polarization resolved photoluminescence spectra of $5\mu \mathrm{m}$ wide wire shaped cavities at $k_{\Vert }=0$. Vertical lines mark the extracted peak energies for each polarization (see text for details). (b) Calculated dispersion along the wire of the lower $j=0,1,2$ modes. The studied scattering mechanism is sketched. Black (grey) traces give the component polarized ⊥ (∥) to the wire axis.

Figure 2

Angle resolved emission under resonant excitation of the lower $1_{\Vert }$ mode. The excitation (detection) is ∥ polarized (⊥ polarized). Logarithmic grey scale over 3.5 orders of magnitude. For clarity the idler emission is multiplied by a factor of $1\times {10}^3$. (a) $P_{\mathit{exc}}=20\mathrm{mW}$. (b) $P_{\mathit{exc}}=300\mathrm{mW}$. (c) Angular dependence of signal (full dots) and idler (open dots) emission at $P_{\mathit{exc}}=300\mathrm{mW}$. The traces have been shifted vertically for clarity.

Figure 3

(a) Signal (full dots) and idler (open dots) intensity (normalized to the signal emission at $P_{\mathit{exc}}^T$) as function of $P_{\mathit{exc}}$. (b) Signal linewidth as function of $P_{\mathit{exc}}$. (c) Emission for ⊥ (black) and ∥ polarization (grey) at a slightly more negative detuning $(P_{\mathit{exc}}=300\mathrm{mW})$. The intensity in the spectral range of the idler is multiplied by a factor of ${10}^3$. (d)–(f) Polarization resolved emission from the $j=0$ mode as the excitation spot (marked by the arrows) is moved along the axis of the wires $(P_{\mathit{exc}}=300\mathrm{mW})$.