Mid-infrared suspended silicon nanomembrane microring resonators with grating couplers

Mid-infrared (mid-IR) silicon photonic integrated circuits have drawn considerable interest to date.However, previous devices are typically designed on silicon waveguide configurations with hundreds of nanometers in thickness, hindering their application in sensing.Here, we demonstrated a suspended nanomembrane silicon (SNS) microring resonator (MRR) at 3.27 m wavelengths with a subwavelength grating coupler.Our experimental results show that the SNS MRR showcases a quality factor of 3500 with a giant confinement factor of 0.89 and reduced thermal sensitivity of 0.07 nm/C.To our knowledge, the study opens a new avenue to developing mid-IR silicon devices for sensing applications.