Compensating for Laser Wavelength Instability in Multiwavelength Digital Holography: The Residual Method for Accurate Heightmap GenerationBalasubrahmaniyam Mukundakumar, Shimpei Matsura, Raiitsu Suzuki and René BarczykEPJ Web Conf., 335 (2025) 01004DOI: https://doi.org/10.1051/epjconf/202533501004