Ultra-precise chip-scale sensor detects unprecedentedly small changes in environmental conditions at the nanoscale

Chip scale high precision measurements of physical quantities such as temperature, pressure and refractive index have become common with nanophotonics and nanoplasmonics resonance cavities. As excellent transducers to convert small variations in the local refractive index into measurable spectral shifts, resonance cavities are being used extensively in a variety of disciplines ranging from bio-sensing and pressure gauges to atomic and molecular spectroscopy. Chip-scale microring and microdisk resonators (MRRs) are widely used for these purposes owing to their miniaturized size, relative ease of design and fabrication, high quality factor, and versatility in the optimization of their transfer function.