Optical thickness measurement with single-shot dual-wavelength in-line digital holography.

ABSTRACT

An algorithm for quantitative reconstruction of the optical thickness distribution of objects is proposed based on single-shot dual-wavelength in-line digital holography. Two single-wavelength holograms can be extracted from a single-shot recorded dual-wavelength in-line hologram. The quantitative optical thickness distribution of the specimen can be reconstructed directly without calculations of the phase images at every single wavelength. Thus, off-axis recording and phase-shifting operation are not required, enabling a fast and high-resolution measurement. The effectiveness and accuracy of the proposed method are verified by both numerical simulations and experimental results.