摘要
We demonstrate a size sensing technique for nano-particles using optical differential phase measurement by a dual fiber interferometer through phase-generated carrier （PGC） demodulation. Nano-particle diameters are obtained from the differential phase shift as a result of adding an optical scattering perturbation into two-beam interference. Polystyrene nano-particles with diameters from 200 to 900 nm in a microfluidic channel are de- tected using this technique to acquire real-time particle diameters. Compared with amplitude sensing with over i0 mW of laser irradiance, particle sizing by PGC phase sensing can be achieved at a laser power as low as 1.18 mW. We further analyze major sources of noise in order to improve the limits of detection. This sensing technique may find a broad range of applications from the real-time selection of biological cell samples to rare cell detection in blood samples for early cancer screening.
We demonstrate a size sensing technique for nano-particles using optical differential phase measurement by a dual fiber interferometer through phase-generated carrier （PGC） demodulation. Nano-particle diameters are obtained from the differential phase shift as a result of adding an optical scattering perturbation into two-beam interference. Polystyrene nano-particles with diameters from 200 to 900 nm in a microfluidic channel are de- tected using this technique to acquire real-time particle diameters. Compared with amplitude sensing with over i0 mW of laser irradiance, particle sizing by PGC phase sensing can be achieved at a laser power as low as 1.18 mW. We further analyze major sources of noise in order to improve the limits of detection. This sensing technique may find a broad range of applications from the real-time selection of biological cell samples to rare cell detection in blood samples for early cancer screening.
基金
supported in part by the National Natural Science Foundation of China(NSFC)under Grant No.61378086
