Light in optical fiber travels in the near-infrared region, far beyond visible light, and choosing the right transmission wavelengths is fundamental for minimizing loss and maximizing bandwidth. This article delves into why 850, 1310, and 1550 nm are standard, what less-known regimes and tradeoffs. For fiber optics with glass fibers, we use light in the infrared region which has wavelengths longer than visible light, typically around 850, 1300 and 1550 nm. The light is a form of carrier wave that is modulated to carry information. Fiber is preferred. An optical wavelength refers specifically to the wavelength of light used in fiber optic communication systems.