We build a two-wavelength off-axis quasi-common-path digital holography for quantitative phase imaging (QPI) using polarization-multiplexing and flipping. The interference is performed by flipping the relative position of a sample and reference beam, and the dual-wavelength information is spatially multiplexed onto a monochromatic CCD camera simultaneously using polarization-multiplexing. Due to orthogonal interference fringes of two-wavelengths, the unwrapped information on the phase and thickness for the sample can be extracted from a single interferogram. Our setup requires no pinholes, gratings or dichroic mirror with straightforward alignment. Additionally, a division algorithm for dual-wavelength off-axis digital holography with the help of a specimen-free multiplexed interferogram is proposed to extract the phase of a specimen. We demonstrate the operation of the setup with step target and circular pillar.

Date Published: 7 March 2019
PDF: 5 pages
Proc. SPIE 11053, Tenth International Symposium on Precision Engineering Measurements and Instrumentation, 110530O (7 March 2019); doi: 10.1117/12.2512018

Published in SPIE Proceedings Vol. 11053:
Tenth International Symposium on Precision Engineering Measurements and Instrumentation
Jiubin Tan; Jie Lin, Editor(s)