Beyond Spectral Resolution in Nanophotonic Sensing: Picometer-Level Precision with Multispectral Readout.

Nanophotonic sensors offer precision, remote read-out, and immunity to electromagnetic interference but face adoption challenges due to complex, costly readout instrumentation, typically based on high resolution. This article challenges the notion that high spectral resolution is necessary for high-performance optical sensing. We propose co-optimizing the line widths of the sensor and readout to achieve picometer-level precision using low-resolution multispectral detector arrays and incoherent light sources. This approach is validated in temperature sensing, fiber-tip refractive index sensing, and biosensing with nanophotonic transducers, achieving superior precision to high-resolution spectrometers. This paradigm change in readout will enable optical sensing systems with costs and dimensions comparable to electronic sensors.