Fabrication and characterization of two concentric microring laser

In this paper, we report the fabrication and characterization of two concentric microring polymer lasers. The experimental results of this laser have been compared with single microring lasers. Experimental results have illustrated that the proposed structure removes all the side modes of the single-ring laser using the Vernier effect, and only one hybrid mode is excited in the structure. To further investigate the experimental results, the numerical simulation of the microlasers has also been investigated, and the numerical results closely follow the accuracy of the experimental results. The proposed laser has excellent capabilities with integrated photonic devices because of its extremely compact dimensions and extremely low power threshold.