Phase retrieval based on the irradiance transport equation and the Fourier transform method: experiments

Area of Science:

• Optics and Photonics
• Wavefront Sensing
• Phase Measurement Techniques

Background:

• Deterministic phase retrieval is crucial for optical metrology.
• Existing methods often rely on interferometry, limiting applications.
• The Teague-Streibl irradiance transport equation provides a theoretical basis for phase recovery from intensity measurements.

Purpose of the Study:

• To experimentally demonstrate deterministic phase retrieval.
• To introduce a new, non-interferometric technique for solving the irradiance transport equation.
• To validate the proposed method through quantitative phase measurements.

Main Methods:

• Utilizing the Teague-Streibl irradiance transport equation.
• Employing a Fourier transform method for solving the transport equation.
• Introducing a high spatial carrier frequency using a grating to encode phase information.
• Performing quantitative phase measurements without interferometry.

Main Results:

• Successful experimental demonstration of deterministic phase retrieval.
• The proposed Fourier transform method effectively solves the transport equation.
• Quantitative phase measurements show excellent agreement with theoretical predictions.
• The technique successfully retrieves phase from intensity distributions.

Conclusions:

• The developed technique offers a viable non-interferometric approach for deterministic phase retrieval.
• This method provides accurate phase measurements, validated by experimental results.
• The use of a grating to create a spatial carrier frequency is effective for phase retrieval.