Continuous counting and sizing of airborne nanoparticles using hollow-core photonic crystal fibres

Excess concentrations of particulate matter (PM) in ambient air cause environmental pollution and can severely damage public health [1]. Although numerous systems have been developed for monitoring atmospheric PM [2], there is still a lack of devices offering high-precision continuous real-time monitoring of particle size and concentration. Although nano-waveguide arrays have been used to size airborne nanoparticles, they are found to degrade rapidly [3]. Here we report a flying-particle system based on the optical capture and propulsion of particles in hollow-core photonic crystal fibre (HC-PCF). It provides continuous particle counting and sizing and is capable of measuring particle diameters from sub-µm to a few µm.