In traditional semiconductor lasers, it is usual to obtain single lateral mode operation by narrowing the ridge of waveguide, which is sensitive to fabrication inaccuracies. To overcome this shortcoming, a quasi-PT (parity-time) symmetric double ridge semiconductor laser is proposed to reach single lateral mode operation for an intrinsic multi-mode stripe laser. The coupled mode theory is used to analyze the non-Hermitian modulation of the gain (or loss) of the PT symmetric double ridge laser to obtain the coupling coefficient between the two ridge waveguides. Finally, the mode field distributions of the quasi-PT symmetric double ridge laser are simulated before and after the spontaneous PT symmetry breaking, which keep the laser operating in single lateral mode.

在传统的半导体激光器中，通常通过使波导脊变窄来获得单横模操作，这对制造误差很敏感。为了克服这一缺点，提出了一种准PT（奇偶校验时间）对称双脊半导体激光器，以实现本征多模条纹激光器的单横向模式操作。耦合模理论用于分析PT对称双脊激光器的增益（或损耗）的非厄米调制，得到两个脊波导之间的耦合系数。最后，模拟了准PT对称双脊激光器在自发PT对称破缺前后的模场分布，使激光器保持在单横向模式下工作。