Dual-Mode Silicon Ring Resonator Based on Subwavelength Grating Directional Couplers

We propose and experimentally demonstrate a dual-mode silicon ring resonator which could process TE₀ and TE₁ modes simultaneously. By introducing subwavelength grating into the coupling region, compact footprint of ∼90 μm × 20 μm is achieved. The proposed device is fabricated on the standard silicon-on-insulator platform. The measured results indicate the mode crosstalk within C band are less than −12.2 and −11.5 dB for TE₀ and TE₁ modes, respectively. Furthermore, heaters for resonant wavelength tuning are fabricated and measured with good uniformity for both modes.