Research on optical transfer function measurement based on Hartmann wavefront sensor

This study proposes a Hartmann wavefront sensor-based method for cost-effective, real-time measurement of Optical Transfer Function (OTF). First, an OTF measurement framework is established using wavefront data acquired through the Hartmann wavefront sensor. Subsequently, we design an optical configuration for OTF measurement, incorporating methodologies to determine depth of focus, characterize aberrations, and measure focal length. A dedicated calibration optical path is developed for objective lens aberration quantification, accompanied by systematic calibration procedures. Finally, an experimental setup is implemented to comprehensively assess lens performance, including Modulation Transfer Function (MTF), aberration, focal length, depth of focus, and chromatic aberration. The measurement results show that this method can achieve MTF measurement for the lens within a 0−1° field of view. The measured aberrations include astigmatism (0.114 λ), coma (0.128 λ), and spherical aberration (0.02 λ). At 0° field angle, the chromatic aberration values for red, green, and blue wavelengths are 0.047 λ, 0.055 λ, and 0.048 λ, respectively, increasing to 0.117 λ, 0.176 λ, and 0.154 λ at 1° field angle. The depth of focus is measured at 0.454 mm with a 2% error, while the focal length is determined to be 74.6 mm with a 0.8% error. These results confirm that the proposed measurement method enables accurate MTF characterization of optical lenses, providing a low-cost and real-time technical solution for the evaluation of MTF in optical systems.