Phase retrieval from a high-numerical-aperture intensity distribution by use of an aperture-array filter

Area of Science:

• Optics
• Imaging Science
• Computational Physics

Background:

• Noninterferometric phase-retrieval methods in coherent diffractive imaging typically rely on low numerical aperture systems.
• High numerical aperture is crucial for achieving high spatial resolution in microscopy applications.
• Existing methods often use Fresnel or Fraunhofer approximations, which are insufficient for high numerical aperture imaging.

Purpose of the Study:

• To extend existing phase-retrieval methods to high numerical aperture systems.
• To enable high-resolution object reconstruction in microscopy.
• To retrieve depth information from objects using advanced imaging techniques.

Main Methods:

• Utilizing an aperture-array filter-based phase-retrieval method.
• Applying the first Rayleigh-Sommerfeld integral for spherical wave propagation.
• Replacing the Fresnel integral with a more accurate wave propagation model for high numerical aperture.

Main Results:

• Demonstrated successful object reconstruction at high lateral resolution in computer simulations.
• Successfully retrieved information regarding the depth direction of the object.
• Validated the extension procedure for high numerical aperture imaging systems.

Conclusions:

• The proposed extension procedure effectively adapts phase-retrieval methods for high numerical aperture systems.
• This advancement is critical for high-resolution microscopy and 3D object reconstruction.
• The method overcomes limitations of previous approximations in demanding imaging scenarios.