The fiber latency calculator helps determine the time it takes for data to travel through a fiber optic cable between two points. In free space, light travels at 299,792,458 meters per second. In fiber optics, the. Fiber-optic communication is a form of optical communication for transmitting information from one place to another by sending pulses of infrared or visible light through an optical fiber. Fiber is preferred. Optical time–frequency transfer establishes the metrological linkage in large-scale clock networks, which facilitates various applications. Light signals transmitted through fiber optics travel at approximately 200,000 km/s, which is slower than the speed of light in a vacuum (300,000 km/s) due to.