What is water peak in fiber optic?

The water peak in fiber optics refers to a specific phenomenon where the attenuation of light increases significantly due to the presence of water molecules in the fiber's glass structure. This peak typically occurs around the wavelength of 1383 nm and results from the vibrational modes of the hydroxyl (OH) groups in the glass, which absorb certain wavelengths of light. As a result, fibers with high water content can experience increased losses at this wavelength, impacting the overall performance of optical communication systems. Minimizing water content during fiber manufacturing can help reduce the effects of the water peak.