title: Nanoparticle detection using dual-phase interferometry.
abstract: The detection and identification of nanoparticles is of growing interest in atmospheric monitoring, medicine, and semiconductor manufacturing. While elastic light scattering with interferometric detection provides good sensitivity to single particles, active optical components prevent scalability of realistic sizes for deployment in the field or clinic. Here, we report on a simple phase-sensitive nanoparticle detection scheme with no active optical elements. Two measurements are taken simultaneously, allowing the amplitude and phase to be decoupled. We demonstrate the detection of 25 nm Au particles in liquid in Δt ∼ 1 ms with a signal-to-noise ratio of ∼ 37. Such performance makes it possible to detect nanoscale contaminants or larger proteins in real time without the need of artificial labeling.
authors.affiliation: Institute of Optics, University of Rochester, Rochester, New York 14627, USA. bdeutsch@optics.rochester.edu
authors.forename: Bradley
authors.initials: B
authors.lastname: Deutsch
authors.forename: Ryan
authors.initials: R
authors.lastname: Beams
authors.forename: Lukas
authors.initials: L
authors.lastname: Novotny
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D006046:Gold / Q000032:analysis; D007368:Interferometry / Q000295:instrumentation / Q000379:methods*; D053758:Nanoparticles / Q000032:analysis*; D012542:Scattering, Radiation
chemical_list: D006046:Gold