Figure 1: An optical fiber-based spectral-domain OCT scanner. The system uses a low-coherence light source to launch light into both sample (Path 2) and reference (Path 1) arms. In the sample arm, a set of galvanometric mirrors raster-scan the sample under test. Light that is collected back from the reference and sample arms recombines to form interference patterns which are detected by the spectrometer (Path 3).