Triple-wavelength quantitative phase imaging with refractive index measurement

•A method based on triple-wavelength quantitative phase imaging to quantitatively measure the refractive index (RI) and the topography of transparent samples is proposed.•No needs of special highly dispersive medium, additional assistant technology and manual operation did anymore as the existed methods in the proposed method.•The experimental configuration based on quadriwave lateral shearing interferometry (QLSI) is simple and compact, and has high stability.•From the measured RIs, the composition of the sample can be identified besides the topography of the sample, and the proposed method is anticipated to be an effective and potential tool in RI and topography measurement of optical materials and identification of substance sort.