Wavefront Characterization with Shack–Hartmann versus Phase Retrieval

Computational holography relies on the characteristics of the light source for next-generation display technologies and microscopy. For high-quality color holography, however, the optical field emitted by the light source will need to be accurately characterized. Variations in amplitude, divergence, and wavefront could introduce optical aberrations and degrade holographic image quality.

This project aims to develop a wavefront characterization method for emerging color light sources and to systematically compare Shack–Hartmann wavefront sensing with camera-based phase retrieval.

Objectives

The main objectives are to:

• Characterize the wavefront emitted by the light source at different wavelengths.
• Compare Shack–Hartmann sensing and phase retrieval in terms of accuracy, spatial resolution, sensitivity, repeatability, and measurement complexity.
• Quantify wavefront aberrations using phase maps and Zernike decomposition.
• Investigate wavelength-dependent wavefront variations between blue, green, and red emission.
• Demonstrate how the measured wavefront could be used for SLM-based wavefront compensation and color CGH.

Expected Outcomes

The project is expected to establish a quantitative comparison between Shack–Hartmann sensing and phase retrieval for wavefront characterization, together with a practical wavefront calibration method for color computational holography.

The resulting framework could subsequently be extended toward automated wavefront calibration for high-quality color holographic displays.

Supervisors: Hyun-su Kim (hyun-su.kim@imec.be) and Raees Muhamad (Raees.Kizhakkumkara.Muhamad@vub.be)