Mitigation of interlayer crosstalk during 3D phase reconstruction using multi-wavelength digital holography

Suppressing inter-layer crosstalk or interference is an important problem in three-dimensional (3D) digital holographic reconstruction. Accurate layer separation is essential for volumetric imaging, depth-resolved visualization, and quantitative phase measurement. Here, we propose a scheme to achieve this using multi-wavelength digital holography, with the number of wavelengths selected to be equal to the number of layers. As an example, longitudinally separated layers with individually unique phase information have been numerically propagated and recorded holographically using different wavelengths to simulate a composite multispectral computer-generated hologram, which is thereafter reconstructed with minimal inter-layer crosstalk. Due to the wavelength-dependent phase accumulations, the out-of-focus contributions to a desired image plane for every reconstruction wavelength are distinctly different, which enables the separation of individual image planes during reconstruction. The final unwrapped phase is recovered using transport of intensity (TIE) around each image plane.