Key parameters include center wavelength, transmitter output power (Tx), receiver sensitivity (Rx), and the optical budget (Tx–Rx margin). The optical budget must exceed total link loss plus a safety margin to ensure reliable performance. 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. Center wavelength 1) 850nm (MM, multi-mode, low cost, but short transmission distance, usually only. Dispersion limits fiber optic transmission distance by causing signal distortion and is classified into chromatic dispersion, modal dispersion, and polarization mode dispersion (PMD).