List some passive optical devices

Passive optical devices are components that manage, split, combine, or redirect light in fiber optic networks without requiring external power.Passive optical devices are essential in fiber optic systems because they manipulate light signals using physical principles like reflection, refraction, and interference without amplifying or electronically processing the signal . Some common passive optical devices include:Optical Couplers and Splitters: Combine or divide light signals among multiple fibers, often used in broadband distribution and wavelength multiplexing .Optical Filters: Selectively transmit or block specific wavelengths, enabling Wavelength Division Multiplexing (WDM) and signal routing .Optical Attenuators: Reduce signal intensity to prevent receiver overload or optimize power levels .Optical Circulators: Direct light sequentially through multiple ports, separating forward and reverse paths in a network .Optical Isolators: Allow light to pass in one direction while blocking backward reflections, protecting lasers and amplifiers .Optical Connectors and Splices: Provide permanent or detachable connections between fibers, ensuring low insertion loss and reliable signal transmission .Optical Add/Drop Multiplexers (OADM): Add or remove specific wavelength channels from a fiber without affecting other channels . These devices are widely used in telecommunications, data centers, and fiber laser systems, providing reliable, low-maintenance solutions for routing and managing optical signals in complex networks .