Design of a Full-Field Optical Coherence Tomography (OCT) 3D-Scene Imaging Setup

OCT is a useful non-destructive imaging technique that does not generate ionizing radiation like other medical imaging techniques (X-ray, CT, PET). Another bonus is that this technique can achieve much higher resolutions than other imaging modalities such as ultrasound or MRI: up to ~10 μm at a sample depth of 1 to 2 mm. OCT is analogous to ultrasound; instead of sound waves reflecting within the sample to generate the image, near-infrared light is used instead. First, two beams are produced from a broadband radiation source – one is passed through the sample while the other remains a reference signal. Upon recombination of the two beams, interference occurs, and the light that was absorbed or reflected by the sample contains the information that is used to generate an image. OCT can be used in a variety of different applications where nondestructive imaging is required. It can be used in industry for material characterization (material thickness in silicon wafers, surface roughness) and it can be used in multiple medical fields: it can image the retina of the eye, coronary arteries, and to detect and diagnose cancer and precancerous lesions. The goal of this project was to design an imaging setup that utilized OCT to measure the topography of centimeter-scale objects that could achieve a spatial resolution of up to approximately 50 micrometers.