Speckle decorrelation with wavelength shift as a simple way to image transport mean free path Alesya Mikhailovskaya, Julien Fade and Jérôme Crassous Eur. Phys. J. Appl. Phys., 85 3 (2019) 30701 Published online: 26 April 2019 DOI: 10.1051/epjap/2019180297