Light detectors only capture the intensity variations of electromagnetic waves interacting with an object/sample, resulting in the loss of the phase information, which is highly sensitive to even minor optical path length changes.
Holography is a method to record both the amplitude and phase of the wavefront interacting with the sample (object wavefront), by combining it with a reference wavefront, leading to interference fringes, called holograms.
In digital holography, these interference fringes are sampled using a digital array and reconstructed by numerical methods yielding the amplitude and phase of the object wavefront. Digital holographic imaging provides high-contrast images of even transparent specimens as well their thickness/height profile. This approach also allows comparing wavefronts recorded at different times, leading to holographic interferometry which finds application across various domains, from nanometer-level deformation measurement to quantitative phase microscopy.
The presentation will explore our work on the development of digital holographic techniques for quantitative phase imaging of diffuse and transparent macro and microscopic samples for their characterization, identification, and classification.