A novel method for reducing the appearance of speckle within a single image acquisition in optical coherence tomography is presented. Local variations in the optical path length of beamlets within the beam diameter are introduced by vibrating a thin water film placed in a collimated section of the sample arm beam path. Consequent averaging of small numbers of adjacent depth scans results in a reduced appearance of speckle with no change in the axial point spread function. Reduced speckle images of a layered agar sample and thin reflective surfaces are shown.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.