Post-fabrication tuning of microring resonators using 3D-printed microfluidics.

We demonstrate a method of tuning the resonant frequencies of silicon microring resonators using a 3D-printed microfluidic chip overlaid directly on the photonic circuit with zero energy consumption following the initial tuning. Aqueous solutions with different concentrations of NaCl are used in experimentation. A shift of a full free spectral range is observed at a concentration of 10% NaCl. On a 60 µm microring resonator, this equals a resonant wavelength shift of 1.514 nm when the index of the cladding changes by 0.017 refractive index units (RIUs), or at a rate of 89.05 nm/RIU.

Automated Photonic Tuning of Silicon Microring Resonators Using a 3D-printed Microfluidic Mixer.

We demonstrate a novel method to automate tuning of microring resonators using 3D-printed microfluidic control capable of resonance wavelength shifts of 4 nm. We use a custom 3D-printer that can fabricate microfluidic devices with sub-10 µm features and that perform automatic pumping, mixing, and dilution operations.