Optical passive components are devices used in fiber optic networks that control and manipulate light signals without using power, electricity, or electronics. They are called "passive" because they do not require external power to operate. Optical passive components provide essential functions like combining, splitting, multiplexing, demultiplexing, and monitoring light in a fiber network.

Examples of optical passive components include fiber optic splitters, couplers, multiplexers, filters, attenuators, isolators, and wavelength division multiplexers (WDMs). These devices utilize properties like interference, diffraction, and refraction to affect light passing through optical fiber without converting the light into electrical signals. Passive components contain no active electronics parts - they are made from optical fiber, glass, or plastic.

Optical passive components are reliable, compact, cause less signal loss, and are cost-effective compared to active electronics. They allow engineers to optimize optical networks through functions like dividing fibers, combining wavelengths, blocking unwanted light, and controlling power levels. Proper installation and care is required as dirty or damaged passive components can disrupt signals. Fiber networks rely extensively on passive components for effective transmission and distribution of vast data loads.