The typical diameter of an optical fiber is 125 microns, which increases to 250 microns if we consider the thickness of the standard acrylate coating. Multimode fibers are typically used for temperature sensing, while single-mode fibers are primarily used for distributed acoustic or strain sensing. Although temperature and acoustic sensors can be used with both single-mode and multimode fiber, the performance of the temperature system is optimized when it is used with multimode. Acoustic sensor performance is optimized with single-mode fiber.
Fiber optic cables can contain multiple fibers, which can be of the same type or a combination thereof. The design of the cable depends on installation, operation, and application conditions.