Optical passive components are the quiet workhorses in fiber systems. They don't add gain or require power, but they decide how efficiently, cleanly, and safely light moves through your network or laser chain. This guide blends clear definitions with engineer-grade selection criteria, with a. Some of the most common optical passive components include optical couplers, optical splitters, optical filters, optical connectors, optical attenuators, optical circulators, optical isolators, optical switches, and optical add/drop multiplexers. In this use, a PON. Optics engineering focuses on transmitting data using light, a method providing the high speeds and vast bandwidth necessary for modern digital life.