title: Three-dimensional subpixel estimation in holographic position measurement of an optically trapped nanoparticle.
abstract: We propose three-dimensional (3D) subpixel estimation in the position measurement of a nanoparticle held in optical tweezers in water by using an in-line, low-coherence digital holographic microscope. The 3D subpixel estimation was performed with the addition of axial subpixel estimation to the lateral subpixel estimation introduced in our previous work [Appl. Opt.50, H183 (2011)]. The axial subpixel estimation allowed the step length in the diffraction calculation of a hologram to be increased to ~20 nm while keeping the axial resolution of ~3 nm. This drastically decreased the computation time of the diffraction calculation to less than 10% of the two-dimensional subpixel estimation.
authors.affiliation: Center for Optical Research and Education (CORE), Utsunomiya University, 7-1-2 Yoto, Utsunomiya 321-8585, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sato
authors.forename: Quang Duc
authors.initials: QD
authors.lastname: Pham
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hayasaki