Fiber optic power meters can use single-mode and/or multi-mode optical cable. Single-mode cable allows only one mode to propagate and features very small core diameters of approximately 8 µm.

Multimode Multimode fiber optic cables support the propagation of multiple modes. Multimode fiber may have a typical core diameter of 50 to 100 µm with a refractive index that is graded or stepped. It ...