Compensation of field-dependent lateral chromatic aberrations in multiwavelength digital holography

Multiwavelength digital holography (MWDH) enables surface measurements with sub-micrometer precision, even for optically rough surfaces. The use of synthetic wavelengths reduces speckle effects and unambiguity issues. This work addresses challenges in MWDH related to field-position dependent lateral chromatic aberrations, especially when using small synthetic wavelengths. These are achieved by combining spectrally distant phase-maps, e.g. corresponding to the red and green spectrum of light. We present a novel fiber-based calibration procedure and a compensation technique for field-position dependent chromatic aberrations, ensuring near-diffraction-limited measurements across the entire field of view (FOV). Experimental validation demonstrates significantly improved lateral resolution and supports more cost-effective sensor designs, even for industrial applications.