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[摘要]：A particle sizing algorithm is developed for nanoparticle sizing with laser Doppler anemometry/velocimetry systems. A model-based signal processing method is used to estimate the particle size from the autocorrelation curve corresponding to a single particle transit. Two kinds of figures of merit functions are combined to improve the sensitivity. The optimal setup parameters (refractive index, wavelength, and observation direction) and trajectory error are investigated in independent simulation studies. At 514-nm illumination wavelength, the most sensitive size region is found below 300 nm down to the sizing limit (20 photons on average from a single particle transit). The required laser power is searched for by the lower sizing limit based on the calibration measurement. The size estimation of a polystyrene sphere particle of 50 nm diameter requires at least 123-kW/cm(2) laser power density at 350 nm, while 587 kW/cm(2) at 514 nm is used in the studied system. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3292002] |
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