Source diversity for transport of intensity phase imaging

Area of Science:

• Optics and Photonics
• Image Reconstruction
• Phase Retrieval

Background:

• The transport of intensity equation (TIE) is a widely used phase retrieval technique.
• TIE reconstructs phase from intensity measurements but is sensitive to low-frequency noise.
• Köhler illumination with limited power/exposure can cause blurring when using larger sources to mitigate noise.

Purpose of the Study:

• To address the limitations of TIE phase reconstruction, specifically susceptibility to low-frequency noise.
• To investigate methods for improving both low- and high-frequency performance in TIE.
• To explore the impact of source size diversity on phase reconstruction quality.

Main Methods:

• Utilized the transport of intensity equation (TIE) framework.
• Acquired intensity measurements of a paraxial field at multiple propagation distances.
• Employed Köhler illumination with varying source sizes.
• Developed a method to combine intensity data from diverse source sizes.

Main Results:

• Demonstrated that combining intensity measurements from different source sizes improves phase reconstruction.
• Showcased enhanced performance in both low-frequency and high-frequency regimes.
• Successfully mitigated low-frequency noise artifacts inherent in standard TIE.

Conclusions:

• A novel approach combining intensity measurements from diverse source sizes significantly enhances TIE phase retrieval.
• This method offers a robust solution for improving phase reconstruction quality, particularly under challenging illumination conditions.
• The findings pave the way for more accurate and reliable phase imaging in various optical applications.