What is the current standardization for the outside diameter (OD) of the cladding in single-mode fiber?

The correct choice reflects that the current standardization for the outside diameter (OD) of the cladding in single-mode fiber is indeed 125 µm, with an accuracy of ±1 µm. This specification is essential as it ensures uniformity and compatibility in fiber optic networks. The standardization helps in minimizing losses and maximizing performance in fiber optic communication systems.

Single-mode fibers typically have a core diameter of about 8 to 10 µm and a cladding diameter of 125 µm. This specific measurement is crucial because the precise dimensions contribute to the effective guidance of light through the fiber, thus affecting signal quality. Adhering to the standardized cladding diameter helps manufacturers create fibers that are interchangeable, allowing for seamless integration into existing infrastructure.

Understanding the accuracy tolerance of ±1 µm further emphasizes the importance of precision in fiber optics. Such tight tolerances ensure that even slight deviations will not significantly affect the fiber's performance. In contrast, the other options present measurements that do not conform to the established standards for single-mode fiber cladding, which would lead to compatibility issues and potential degradation in signal transmission.