Fiber optic couplers, also known as fiber optic splitters, are devices used to split or combine optical signals in fiber optic networks. They play a crucial role in various applications, such as telecommunications, data centers, and fiber-to-the-home (FTTH) installations. In this comprehensive. The working principle of these couplers is based on the phenomena of lightwave technology, including refraction, reflection, and interference. It functions by dividing a single incoming light path into multiple outgoing paths, or by combining light from several input paths into a single output fiber.