Relaxing the alignment and fabrication tolerances of thin annular folded imaging systems using wavefront coding

Area of Science:

• Optics and Photonics
• Image Processing

Background:

• Annular folded imagers offer significant thickness reduction compared to full-aperture systems.
• However, these imagers face challenges with tight fabrication tolerances and limited depth of focus.
• Wavefront coding is a known technique to extend depth of focus in conventional imaging.

Purpose of the Study:

• To investigate the application of wavefront coding to annular folded imaging systems.
• To compare the design and experimental performance of such a system.

Main Methods:

• Implementation of wavefront coding using specialized optics and post-detection signal processing.
• Design and fabrication of a compact annular folded imager with a 38 mm focal length and 5 mm total track.
• Experimental validation of the system's imaging capabilities.

Main Results:

• Demonstration of wavefront coding's effectiveness in improving the depth of focus for annular folded optics.
• Successful design and testing of a significantly thin imaging system.
• Quantification of performance trade-offs associated with the combined technologies.

Conclusions:

• Wavefront coding is a viable strategy to enhance the depth of focus in thin annular folded imagers.
• This approach can mitigate the inherent depth of focus limitations of annular optics.
• Enables the development of more compact and versatile imaging devices.