Imaging properties of three refractive axicons

Area of Science:

• Optics and Photonics
• Image Processing

Background:

• Refractive axicons are optical elements that generate non-diffracting Bessel beams.
• Understanding their imaging properties is crucial for applications in optical systems.
• Previous research has explored various axicon designs, but a direct comparison of their imaging performance with denoising applications is limited.

Purpose of the Study:

• To experimentally and numerically characterize the imaging properties of linear, logarithmic, and Fresnel refractive axicons.
• To evaluate the utility of their point spread functions (PSFs) in digital image denoising.
• To compare the imaging performance of these three distinct axicon types.

Main Methods:

• Experimental measurement of point spread functions (PSFs) for each axicon type within an imaging system.
• Numerical simulation of axicon imaging properties and PSF variations.
• Development and application of digital filters utilizing the obtained PSFs for image denoising.
• Comparative analysis of imaging performance metrics across the three axicon designs.

Main Results:

• Point spread functions (PSFs) were found to vary along the depth of field for all three axicon types.
• The characterized PSFs were successfully employed in digital filters to effectively denoise images.
• Quantitative and qualitative comparisons revealed differences in the imaging performance of linear, logarithmic, and Fresnel axicons.

Conclusions:

• Refractive axicons exhibit unique imaging characteristics that are dependent on their design (linear, logarithmic, Fresnel).
• The point spread functions (PSFs) derived from these axicons can be effectively utilized for image denoising applications.
• This comparative study provides valuable insights for selecting appropriate axicon designs for specific optical imaging and processing tasks.