Tissue-simulating Intralipid phantoms, chicken breast tissue, and porcine buccal tissue were each used as turbid scattering samples. The scattering layer was constructed by sandwiching the Intralipid solution (Liposyn II, Hospira, Lake Forest, Illinois) or tissue sample between two glass microscope slides, which facilitated comparison of measurements acquired with different instruments. For the Intralipid phantoms, the glass slides were separated by a physical thickness of , and the concentration of Intralipid was varied between 0.2% and 4.0% ( Intralipid phantoms). A constant thickness across all Intralipid samples was chosen to reduce experimental error in phantom construction. The tissue samples were prepared with a Stadie–Riggs tissue slicer (Thomas Scientific, Swedesboro, New Jersey) and varied in thickness between 250 and ( chicken breast tissue samples) and 250 and ( porcine buccal tissue samples). The optical path length (i.e., ) of each sample was measured with an optical coherence tomography (OCT) system (Spark DRC, Wasatch Photonics Inc., Durham, North Carolina). The refractive index of the Intralipid or tissue sample was then used to convert each measurement to physical length.29 Representative OCT images of an Intralipid phantom and a sample of porcine buccal tissue are shown in Fig. 1.