In modern optical communication systems, optical receivers are used in a wide range of applications, including fiber optic communications, optical interconnects, and optical sensing. The. Digital receivers detect the input optical signal coming through an optical fiber, do the amplification of digital photo current, then reshape the signal to produce an undistorted output electrical signal. It's the endpoint of any fiber optic link, sitting at the far end of the cable and translating pulses of infrared light into the ones. Understanding what indoor optical receivers do, how they fit within the broader HFC architecture, and what technical specifications govern their performance is essential knowledge for network engineers, system integrators, and procurement professionals working in cable and broadband infrastructure. Fiber optic receivers are components designed to convert optical signals into electrical signals for further processing in a wide range of modern communication systems.