What unit is used for measuring the diameter of a fiber?

The correct choice for measuring the diameter of a fiber is expressed in microns. Microns, also known as micrometers, are extremely small units of measure that are suitable for the typically very thin strands of fiber optics or other filaments. One micron is one-millionth of a meter, making it ideal for quantifying the fine details of fibers, which often have diameters in the range of a few microns or tens of microns.

While millimeters, inches, and centimeters are all valid units of measurement for various applications, they are comparatively larger and are not as appropriate for the context of measuring fiber diameters. For reference, a human hair is approximately 70 microns in diameter, illustrating how much more precise microns are for such measurements. This high level of precision is essential in fields like fiber optics, where small variances can significantly impact performance.