Mid-infrared GaAs/AlGaAs micro-ring resonators characterized via thermal tuning

Micro-ring resonators with a decoupling waveguide have been manufactured from GaAs/Al0.2Ga0.8As, accommodating mid-infrared wavelengths, and were characterized via thermal tuning. A Q-factor of 1900, a thermal full width at half maximum of 8 degrees C, and a thermal free spectral range of 18 degrees C have been achieved. The low Q-factor indicates comparatively high coupling efficiency from the input waveguide into the decoupling waveguide. The micro-ring resonators shown herein are suitable structures for advanced mid-infrared chem/ bio sensing strategies via resonant-cavity enhancement. In addition, they offer high spectral resolution for evanescent field sensing strategies via effective wavelength demultiplexing waveguide structures.