Optical Coherence Tomography (OCT) is a novel clinical technology that is widely used in ophthalmology and other medical fields. The technology provides two and three dimensional, cross-sectional, micron-scale images of biological tissues within optical scattering media. This technology has been used extensively for imaging tissue microstructure in various medical fields ranging from ophthalmology to gastroenterology. OCT primarily used two types of light sources for the imaging process- a) Femtosecond Lasers or b) Superluminescent Diodes (SLD). However, the high prices and difficult operation of Femtosecond lasers have throttled its widespread adoption in medical applications. At the same time, it has ultimately paved the way for superluminescent diodes for optical coherence tomography in the clinical industry. So, Let's understand what superluminescent diode is and what OCT is in brief.