Separation of the first-order image of the particle field in off-axis focused-image holography

The separation of multiple images is considered in the context of designing holographic image-focused particle diagnostic systems. Two techniques have been employed to determine the minimal directional cosine of the reference wave that ensures the separation of the first-order image of the particle field from the higher-order undesired images. The first approach is based on tracing the rays through the reconstructed images of the particles situated within the sample volume, whereas the second approach relies upon the analysis of the spectra of the reconstructed waves in the spatial-frequency domain. The results obtained by these techniques are compared and discussed.