A Single-Mode Laser Based on Parity-Time-Symmetry Structured Vertical Bragg Reflection Waveguide

A parity-time symmetric vertical Bragg reflection waveguide structure is proposed and analyzed for realizing single-mode operation of a laser diode. Impact of the key design parameters on laser performance are investigated for the purpose of achieving high side-mode suppression ratio and high injection slope efficiency. Our studies indicate that an electrically pumped edge-emitting single-mode laser is possible with proper design. Such lasers exhibit a number of highly desirable and in some cases unique characteristics, such as high-modulation bandwidth, high transverse gain, and high confinement of optical field in the low-effective index Fabry-Perot cavity.