Connect your fiber optic flashlight to one end of a strand of fiber (with most fiber optic flashlights, you must terminate the fiber). Take a look at the opposite end. PortBright™, a built-in flashlight, illuminates dark areas and dense panels. Fiber inspection scope camera with autofocus for stable images in few seconds. Large display to view single-mode and. Is that fiber-optic link really lit? In this quick networking tutorial I show two eye-safe methods to test any single-mode or multi-mode fiber patch lead, no expensive meter required. more. Single-mode fibers (also called monomode fibers) are optical fibers which are designed such that they support only a single propagation mode (LP 01) per polarization direction for a given wavelength. Higher-order modes like LP 11, LP 20 etc. Modes are the possible solutions of the Helmholtz equation for waves, which is obtained by combining. Network cables, known as fiber optics, allow data to be transmitted using pulses of light that travel along the fiber. Glass or plastic are often used to make these fibers.