Wideband Tuning and Deep-Tissue Spectral Detection of Indium Phosphide Nano-Laser Particles.

Cho, Sangyeon; Moon, Wonjoon; Martino, Nicola; Yun, Seok Hyun · Adv Mater · 2025

basic_science · Level V

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Abstract

Laser particles (LPs) emitting narrowband spectra across wide spectral ranges are highly promising for high-multiplex optical barcoding of biological cells. Here, LPs based on indium phosphide (InP) nanodisks are presented, operating in the near-infrared wavelength range of 740-970 nm. Utilizing low-order whispering gallery resonance modes in size-tuned nanodisks, an ultrawide color palette with 25% spectral utilization and nanometer-scale linewidth is achieved. A simple theoretical model accurately predicts spectral ranges based on particle size. The minimum laser size is 430 nm in air and 560 nm within cells, operating at mode orders of 4 or 5. The high brightness and narrow linewidths of polymer-silica-protected InP LPs, combined with a silicon-detector spectrometer, enable spectral detection of laser peaks with high signal-to-background ratios in highly-scattering media, including 1-cm-thick chicken breast tissue and blood vessels in live mice.

Medical subject headings