Three-dimensional imaging by partially coherent light under nonparaxial condition

Area of Science:

• Optics and Photonics
• Three-Dimensional Imaging
• Coherent Optics

Background:

• Traditional 3D imaging theories often rely on paraxial approximations.
• Partially coherent light presents unique challenges in 3D reconstruction.
• Accurate modeling of optical systems is crucial for high-resolution imaging.

Purpose of the Study:

• To develop a rigorous theory for 3D imaging under nonparaxial conditions using partially coherent light.
• To introduce a simplified computational method for the 3D nonparaxial transmission cross coefficient (TCC).
• To simulate and analyze phase contrast and Nomarski differential interference contrast (DIC) imaging of 3D objects.

Main Methods:

• Linear system approach to derive image intensity.
• Definition of the 3D nonparaxial transmission cross coefficient (TCC).
• Utilizing multiple 3D fast Fourier transforms for TCC calculation, replacing six-dimensional integrals.
• Simulation of phase contrast and DIC imaging.

Main Results:

• A simplified formula for calculating the 3D TCC was derived.
• The 3D TCC calculation was made computationally efficient via fast Fourier transforms.
• Simulations demonstrated the effectiveness of the model for phase contrast and DIC.
• The proposed 3D DIC model is the most rigorous to date.

Conclusions:

• The developed theory provides a robust framework for 3D imaging with partially coherent light under nonparaxial conditions.
• The simplified TCC calculation method enhances computational efficiency.
• The rigorous 3D DIC model clearly illustrates the optical sectioning effect, advancing 3D imaging capabilities.