Propagation Loss‐Immune Biocompatible Nanodiamond Refractive Index Sensors

Propagation loss is a key impeding parameter affecting accuracy, range, and applicability of fluorescent microscopy techniques. In this work, a new nanophotonic platform for propagation loss mitigated fluorescent imaging using lifetime ratiometric measurement is proposed. By applying this methodology to local parameter sensing, a method for high sensitivity local refractive index measurement via lifetime/energy monitoring of fluorescent crystal color centers is numerically demonstrated. As the base of this platform, biocompatible diamond nanodisk structures are investigated that enable sensitive, propagation loss‐immune monitoring of refractive index changes both in vitro and in vivo.