Holographic Position Measurements of an Optically-Trapped Gold Nanoparticle Using Twilight-Field Microscope

摘要

We demonstrated three-dimensional (3D) position measurements of a gold nanoparticle held in optical tweezers in water. The position measurements were performed with an in-line, low-coherence digital holographic microscope with the twilight-field technique. The position of the optically-trapped nanoparticle with a diameter of 60 nm had an axial variation of 7.6 nm in the standard deviation when a 1070 nm laser beam with an intensity of more than 27 MW/cm was focused with a 1.25 NA objective lens.