Optical Anisotropy and Photopumped Lasing near 250 nm from Semipolar (1102) AlxGa1-xN/AlN Quantum Wells with Cleaved Mirrors

The optical anisotropy of r-plane AlxGa1-xN/AlN quantum wells (QWs) is investigated theoretically and experimentally. Theoretical calculations predict that as the Al composition is increased from 0 to 1, the in-plane polarization switches from E 1 [112 over line 0] to E 1 [11 over line 01] at an Al composition of approximately 0.2. The polarization properties are nearly independent of the well width, particularly when the well width is thicker than approximately 1.5 nm. Photoluminescence spectroscopy of the fabricated r-plane AlxGa1-xN/AlN QWs experimentally confirms the theoretical prediction. The E 1 [11 over line 01] polarization enables the emitted light to propagate along the [112 over line 0] direction. Using this property, photopumped lasing at approximately 250-nm wavelength at 11 K is demonstrated from an r-plane AlxGa1-xN/AlN QW with the cleaved (112 over line 0) a planes as cavity mirrors.

Automated summary

The optical anisotropy of r-plane AlxGa1-xN/AlN quantum wells is investigated, and both theoretical calculations and experimental results confirm the polarization switching at a certain Al composition. The polarization property enables the emitted light to propagate in a specific direction and photopumped lasing is demonstrated on a specific structure of quantum wells.