This study will test a newly developed dual modality probe, including optical coherence tomography (OCT) and angle-resolved low-coherence interferometry (a/LCI), in the human esophagus to determine 1) whether adequate tissue contact can be attained by the probe to acquire high quality images, and 2) to identify if these images can discern whether the imaged tissue is squamous or Barrett's Esophagus (BE) epithelium. This pilot study will test the operating characteristics of the probe and collect data for further optimization of the a/LCI-OCT device.