Comparison Table of Fiber Optic Cable Loss per Kilometer Abstract: Fiber optic cables are widely used in the telecommunications industry due to their high data transmission capacity and low signal loss. This article presents a comparison table of fiber optic cable loss per kilometer, providing valuable information for engineers and technicians in the field. The table is divided into four aspects: single-mode fiber, multimode fiber, graded-index multimode fiber, and polarization-maintaining fiber. 1. Single-Mode Fiber Single-mode fibers are designed to carry a single mode of light with a narrow core diameter. They offer low attenuation rates and are suitable for long-distance communication applications. The comparison table shows that single-mode fibers have the lowest loss per kilometer among all types of fibers. With an average loss ranging from 0.2 dB/km to 0.5 dB/km, they provide excellent signal transmission capabilities over long distances. The low-loss characteristic of single-mode fibers makes them ideal for applications such as long-haul telecommunications networks, submarine communications systems, and high-speed internet connections. 2. Multimode Fiber Multimode fibers have larger core diameters compared to single-mode fibers and can transmit multiple modes simultaneously. The comparison table reveals that multimode fibers generally have higher losses compared to single-mode fibers, with average values ranging from 2 dB/km to 6 dB/km. Due to their higher attenuation rates, multimode fibers are typically used in shorter distance applications such as local area networks (LANs), data centers, and video surveillance systems. 3. Graded-Index Multimode Fiber Graded-index multimode fibers utilize a refractive index profile that gradually decreases towards the outer edges of the core. According to the comparison table results, graded-index multimode fibers exhibit lower losses than standard multimode fibers but still higher than those of single-mode ones. With an average loss ranging from 1 dB/km to 3 dB/km depending on specific designs and implementations, graded-index multimode cables find application in medium-range communication links where both bandwidth capacity and distance requirements need consideration. 4. Polarization-Maintaining Fiber Polarization-maintaining (PM) fiber is specifically designed for maintaining polarization states during light propagation through it. As indicated by the comparison table data, PM fiber exhibits slightly higher losses compared to standard single-mode or graded-index multi-fiber cables, with typical values ranging from 0.5 dB/km up to around 1dB/km depending on various factors including wavelength range utilized or manufacturing techniques employed. This type of optical cable is commonly employed in specialized fields like sensing systems or interferometry setups where maintaining consistent polarization characteristics throughout transmission paths is crucial. In conclusion, the presented comparison table provides engineers with valuable insights into different types of optical cables' performance regarding signal attenuation over distance spans; single mode offers lowest attenuations while PM variants exhibit slightly elevated levels; multimodal options demonstrate intermediate performance levels between those two extremes yet catering well within shorter-range environments like LANs or video surveillance setups; and finally graded index alternatives present themselves as balanced solutions suitable for medium-range deployments combining reasonable bandwidth capacities alongside acceptable attenuations figures