Iterative reconstruction method for the accurate measurement of optical transfer function.

Area of Science:

• Optical Engineering
• Image Science
• Metrology

Background:

• Accurate optical transfer function (OTF) measurement is crucial for characterizing imaging system performance.
• Conventional methods, like using point objects, often suffer from noise and limited accuracy.
• Digital micromirror devices (DMDs) offer a programmable platform for generating precise test patterns.

Purpose of the Study:

• To develop and validate an iterative computation method for reconstructing the OTF of imaging lenses.
• To leverage a digital micromirror device (DMD) for generating diverse test patterns.
• To improve measurement accuracy and reduce noise in OTF determination.

Main Methods:

• An iterative computation algorithm was employed to reconstruct the OTF.
• Multiple images of different patterns displayed on a DMD were recorded.
• The known geometry of DMD micro-mirrors was incorporated into the computation.
• Numerical simulations and experimental validations were performed.

Main Results:

• The proposed iterative method accurately reconstructs the OTF.
• Combining several tens of recorded images significantly reduces measurement noise.
• High measurement accuracy was achieved, surpassing conventional point-object methods.
• Theoretical analysis, numerical, and experimental results confirmed the method's validity.

Conclusions:

• The iterative computation method using DMD-generated patterns provides a highly accurate and robust approach for OTF measurement.
• This technique offers a significant improvement in noise reduction and accuracy over traditional methods.
• The validated method is suitable for precise characterization of imaging lens performance.