Annular multi-focal-phase mask multiplexing based large depth of field imaging by interferenceless coded aperture...

Area of Science:

• Optical Engineering
• Holography
• Microscopy

Background:

• Extending depth-of-field (DOF) is crucial for imaging systems but often requires structural modifications or performance sacrifices.
• Interferenceless coded aperture correlation holography (I-COACH) offers a promising platform for advanced imaging applications.

Purpose of the Study:

• To develop a method for extending the DOF of I-COACH systems without altering optical structure or performance.
• To introduce a novel coded aperture design for large-depth incoherent imaging.

Main Methods:

• Design and implementation of an annular multi-focal coded phase mask (AM-CPM) within the I-COACH system.
• Analysis of axial defocus characteristics and definition of a defocus compensation function.
• Multiplexing the AM-CPM onto the system's optical pupil to act as a gradual lens.

Main Results:

• The AM-CPM effectively compensates for axial defocus aberrations using multi-annular zones with varying focal lengths.
• Simulations and experiments confirmed a continuous axial point spread function distribution.
• The developed method successfully extended the DOF of the I-COACH system with a single exposure.

Conclusions:

• The AM-CPM is an effective solution for extending the DOF of I-COACH systems.
• This approach offers significant potential for applications in microscopic imaging and other fields utilizing I-COACH.
• The method achieves extended DOF without compromising imaging performance or system structure.