Single-mode lasing in a coupled twin circular-side-octagon microcavity

We demonstrate the curvature of coupled twin circular-side-octagon microcavity (TCOM) lasers as the degree of freedom to realize manipulation of mode quality (Q) factor and lasing characteristics. Numerical simulation results indicate that mode Q factors varying from 10(4) to 10(8), wavelength intervals of different transverse modes, and mode numbers for four-bounce modes can be manipulated for five different deformations. Global mode distributes throughout coupled microcavity with mode Q factor around the order of 10(4) or 10(5). Four-bounce modes lase with injection currents applied single microcavity. By pumping both microcavities simultaneously, single-mode lasing for global modes with side mode suppression ratios (SMSRs) of 30, 32, 32, 31, and 36 dB is achieved at the deformation of 0, 0.5, 1, 1.5, and 2 with four-bounce modes suppressed, respectively. Moreover, the linewidths less than 11 MHz for the single mode are obtained with the deformation of 2. The results show that the lasing modes can be efficiently manipulated considering variable curvature for TCOM lasers, which can promote practical applications of microcavity lasers.

Automated summary

This research demonstrates the manipulation of mode quality and lasing characteristics in coupled twin circular-side-octagon microcavity (TCOM) lasers by controlling their curvature. The numerical simulation results show that the mode Q factors, wavelength intervals of different transverse modes, and mode numbers for four-bounce modes can be manipulated through different deformations. Single-mode lasing for global modes with suppressed four-bounce modes is achieved by pumping both microcavities simultaneously. The results highlight the efficient manipulation of lasing modes in TCOM lasers, which can contribute to practical applications of microcavity lasers.