A single strand of glass fiber, called single-mode fiber, is used to transmit single-mode or light beams. It can transmit higher bandwidth than multimode fiber but requires a light source with a limited spectral range. In fiber-optic communication, a single-mode optical fiber, also known as fundamental- or mono-mode, is an optical fiber designed to carry only a single mode of light - the transverse mode. Generally, single mode cable has a narrow core diameter of 8 to 10µm (micrometers), which can propagate at the wavelength of 1310nm and 1550nm.