Reconstruction of phase objects from experimental far field intensities by exponential filtering

Area of Science:

• Optics and Photonics
• Wave Phenomena
• Phase Imaging

Background:

• Phase retrieval is crucial for reconstructing optical properties of transparent objects.
• Far-field intensity measurements are commonly used in phase retrieval techniques.
• Fourier series expansion offers a mathematical framework for signal analysis.

Purpose of the Study:

• To reconstruct the complex amplitude function of phase objects.
• To evaluate the effectiveness of a phase retrieval method using an exponential filter.
• To compare experimental results with theoretical phase profiles.

Main Methods:

• Utilizing a phase retrieval method based on Fourier series expansion.
• Employing an exponential filter during far-field intensity measurements.
• Reconstructing the complex amplitude of a converging lens and circular aperture.
• Acquiring three sets of far-field intensity data.

Main Results:

• Successfully reconstructed the complex amplitude function of the circular aperture.
• Demonstrated accurate phase reconstruction for the tested phase objects.
• Showcased the efficacy of the exponential filter in phase retrieval.
• Achieved close agreement between reconstructed and theoretical phase cross-sections.

Conclusions:

• The exponential filter-based phase retrieval method is effective for reconstructing phase objects.
• The method provides accurate phase information comparable to theoretical models.
• This technique holds potential for applications in optical metrology and imaging.