Effects of third-order spherical aberration on the 3-D incoherent optical transfer function

Area of Science:

• Optics and Photonics
• Image Science

Background:

• Spherical aberration is a common optical aberration affecting image quality.
• The optical transfer function (OTF) is a key metric for characterizing imaging system performance.

Purpose of the Study:

• To derive and analyze the 3-D incoherent optical transfer function (OTF) in the presence of third-order spherical aberration.
• To investigate the impact of spherical aberration on image quality using a structure content parameter.

Main Methods:

• Derivation of the 3-D incoherent OTF expression for systems with spherical aberration.
• Numerical calculation of the normalized OTF for varying aberration levels.
• Calculation of a structure content parameter from the OTF as a quality criterion.

Main Results:

• The influence of spherical aberration on the OTF is highly dependent on the spatial frequency in the longitudinal direction.
• A structure content parameter was derived from the normalized OTF.
• The relationship between the structure content parameter and spherical aberration was accurately modeled by a Cauchy curve for aberrations up to two waves.

Conclusions:

• Spherical aberration significantly alters the 3-D OTF, with effects varying by spatial frequency.
• The derived structure content parameter provides a useful metric for quantifying image quality degradation due to spherical aberration.
• The Cauchy curve fit offers a predictive model for image quality assessment in systems with specific aberration levels.