What might cause an increase in attenuation when testing a fiber optic cable?

An increase in attenuation when testing a fiber optic cable can be caused by improper connections or contamination. When connectors are not seated properly or if there is dirt, dust, or other contaminants on the fiber ends, the light transmission through the fiber can be significantly disrupted. This disruption leads to an increase in signal loss, which is what is referred to as attenuation.

Contamination on the fiber end faces can create a barrier to the effective transmission of light, causing some of the light signal to be absorbed or scattered, thus reducing the overall performance of the fiber optic link. Additionally, improperly terminated connections can result in air gaps or misalignment, leading to increased losses as well. Thus, ensuring clean and properly installed connections is critical for maintaining optimal fiber optic performance and minimizing attenuation.

While excessive length of fiber cable may also contribute to attenuation due to the inherent loss characteristics of the fiber, improper connections or contamination is usually a more immediate concern during installation and testing. High-quality connectors and perfect alignment during splicing typically help to decrease attenuation, not increase it.