Fiber optic transmission wavelengths are determined by two factors: longer wavelengths in the infrared for lower loss in the glass fiber and at wavelengths which are between the absorption bands. Thus the normal wavelengths are 850, 1300 and 1550 nm. Fortunately, we are also able to make. Explore the different wavelength bands used in optical fiber communication, including O, E, S, C, L, and U-bands, with approximate wavelength ranges.