Design of Bottom-Emitting Metallic Nanolasers Integrated With Silicon-On-Insulator Waveguides

We propose and analyze a bottom-emitting metallic nanolaser with a cavity size smaller than one wavelength in three dimensions. We optimize the nanolaser performance by adjusting the thickness of SiN_x insulator layer, pillar radius, p-cladding, and n-cladding layers. With a proper design, we can achieve the TE₀₁ mode lasing with an extremely small effective mode volume of 0.135 (λ₀/n)³ and an ultra low threshold gain of 247 cm^-1. The nanolaser is integrated with a silicon-on-insulator waveguide through a bottom-connected grating coupler. By properly modifying the grating coupler period, fill factor, shift position, and grating height, a high coupling efficiency of 88.5% can be acquired.