What is the primary purpose of the trench or moat in optical fibers?

The primary purpose of the trench or moat in optical fibers is to protect the core. In fiber optics, the core is where light transmission occurs, and it is crucial for the core to be safeguarded against physical damage and environmental factors that could affect performance. The trench or moat surrounds the core and acts as a buffer zone that helps to maintain the integrity of the core by preventing contaminants and physical damage that could compromise light transmission.

This protective feature helps to ensure that the optical fiber remains effective in transmitting signals over distances with minimal interference. By providing a shield, it also contributes to the overall durability of the fiber in various installation environments. Hence, the design focused on protecting the core is essential for the optimal performance of optical fibers in communication systems.