Parallel optical-path-length-shifting digital holography.
The authors propose an optical-path-length-shifting digital holography as a technique capable of single-shot recording of three-dimensional information of objects. With a single image sensor, the proposed technique can simultaneously record all of the holograms required for the in-line digital holography that reconstruct the image of an object from two intensity measurements at different planes. The technique can be optically implemented by using an optical-path-length-shifting array device located in the common path of the reference and object waves. The array device has periodic structure of two-step optical-path difference. The configuration of the array device of the proposed technique is simpler than the phase-shifting array device required for parallel phase-shifting digital holographies. Therefore, the optical system of the proposed technique is more suitable for the realization of a single-shot in-line digital holography system that removes the conjugate image from the reconstructed image. The authors conducted both a numerical simulation and a preliminary experiment of the proposed technique. The reconstructed images were quantitatively evaluated by using root mean squared error. In comparison to single-shot digital holography using the Fresnel transform alone, with the proposed technique the root mean squared errors of the technique were reduced to less than 1/6 in amplitude and 1/3 in phase. Also the results of the simulation and experiment agreed well with the images of an object. Thus the effectiveness of the proposed technique is verified.
Awatsuji
Yasuhiro
Y
Division of Electronics, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan. awatsuji@kit.ac.jp
Koyama
Takamasa
T
Tahara
Tatsuki
T
Ito
Kenichi
K
Shimozato
Yuki
Y
Kaneko
Atsushi
A
Nishio
Kenzo
K
Ura
Shogo
S
Kubota
Toshihiro
T
Matoba
Osamu
O