The FC connector is a fiber-optic connector with a threaded body, which was designed for use in high-vibration environments. It is commonly used with both single-mode optical fiber and polarization-maintaining optical fiber. What are the differences between them? Who is the most popular one? Find the answer in the article. The following guide systematically describes. Understanding fiber connector types—SC/APC, SC/PC, LC/UPC, LC/APC, ST/PC, FC/PC, and FC/APC—is essential for selecting the right interface for your application. Each type varies by shape, polish (APC, PC, or UPC), and return loss performance, which affect PC, UPC, and APC Polish Styles: What's the. Fiber optic connectors are the unsung heroes of modern networking. As data centers, telecom networks, and enterprise infrastructures migrate to fiber.