Lensless computationally defined confocal incoherent imaging with a Fresnel zone plane as coded aperture.

Area of Science:

• Optics and Photonics
• Image Reconstruction
• Computational Imaging

Background:

• Traditional confocal microscopy requires scanning, limiting imaging speed.
• Lensless imaging offers miniaturization and cost reduction potential.
• Coded aperture techniques enable single-shot 3D information acquisition.

Purpose of the Study:

• To develop and validate a single-shot lensless confocal imaging system using a Fresnel zone plate (FZP).
• To demonstrate accurate 3D reconstruction of layered scenes without out-of-focus blur.
• To investigate the impact of FZP thickness on reconstruction accuracy.

Main Methods:

• Utilizing an FZP as a coded aperture for single-shot data acquisition.
• Employing a reconstruction algorithm based on compressed sensing (CS) theory.
• Implementing nuclear norm minimization and hologram segmentation for autofocusing and depth recovery.

Main Results:

• Successful single-shot 3D reconstruction of layered scenes was achieved in simulations and experiments.
• Each layer of the scene was accurately recovered at its corresponding depth.
• Reconstruction accuracy was analyzed, highlighting the importance of FZP thickness in the forward model.

Conclusions:

• The FZP-based lensless confocal imaging system provides accurate single-shot 3D reconstruction.
• The developed algorithm effectively separates information from different depth layers.
• Accurate modeling of FZP physical properties, like thickness, is crucial for precise imaging.