We demonstrate an epitaxial strategy for improving the degree of polarization (DoP) of semiconductor lasers under packaging-induced stress by increasing the intrinsic TE/TM effective refractive-index difference, $n_{\textrm{diff}}^{0}$. Three distinct epitaxial structures with $n_{\textrm{diff}}^{0}$ values of 4.75 × 10−4, 9.09 × 10−4, and 1.24 × 10−3 were designed and fabricated. At 14 A, the measured DoP increased from 90.2% to 97.3% with increasing $n_{\textrm{diff}}^{0}$.
