Figure 1

(a) Waveguide geometry for (110) samples. Pump and probe propagate in the $[1\overline{1}0]$ direction. TM indicates polarization along the [110] growth axis; TE indicates polarization along [001]. (b) Selection rules for the HH and LH excitons in the QW. (c) 4 K probe absorption for TE-(red solid line) and TM-(dashed blue line) polarized light from the $170\mu \mathrm{m}$-long waveguide.Reuse & Permissions

Figure 2

Degree of circular polarization of the HH exciton luminescence taken off the facet of the (110) (black squares) and (001) (open blue circles) waveguide samples when pumped at energies across the LH resonance at 4 K.Reuse & Permissions

Figure 3

(a) Representative differential transmission trace showing the change in probe transmission in the presence of the pump beam plotted against the pump-probe detuning. Solid line is a two-Lorentzian fit from which the spin splitting $\Delta f$ is obtained. (b) Splitting $\Delta f$ of the two peaks as in (a) versus the photon energy $E$ of the pump minus the LH transmission minimum $E_0$. $\Delta f$ of the (110) (black squares) and (001) (open blue circles) samples measured at a TM-pump power of 4 mW (TE probe 0.4 mW). Apparent $|g^{*}|$ corresponding to $B_{\mathrm{ext}}=0.23\mathrm{T}$.Reuse & Permissions

Figure 4

(110) waveguide spin splitting $\Delta f$ vs energy from the LH minimum $E_0(T)$ with a TM pump (solid symbols) and TE pump (open symbols) at varying pump power levels: 4 mW (purple squares), 10 mW (blue circles), 20 mW (green triangles), 30 mW (yellow diamonds), and 40 mW (red pentagons). $|g^{*}|$ scale with $B_{\mathrm{ext}}=0.23\mathrm{T}$ only. The spectral and polarization dependences vanish by 60 K.Reuse & Permissions