The light we are most familiar with is of course the light we can see with the naked eye. Our eyes are very sensitive to purple light with a wavelength of 400nm to red light at 700nm. But for optical fibers that carry glass fibers, we use light in the infrared region. These lights have longer wavelengths, less damage to the optical fibers, and are invisible to the naked eye. This article will give you a detailed description of the wavelength of the optical fiber and why you should choose these wavelengths.
Definition of wavelength
In fact, light is defined by its wavelength. Wavelength is a number representing the spectrum of light. The frequency, or color, of each light has a wavelength associated with it. Wavelength and frequency are related. Generally speaking, short-wave radiation is identified by its wavelength, while long-wave radiation is identified by its frequency.
Common wavelengths in optical fibers
The typical wavelength is generally 800 to 1600nm, but as of now, the most commonly used wavelengths in optical fibers are 850nm, 1300nm and 1550nm. Multimode fiber is suitable for wavelengths of 850nm and 1300nm, while single mode fiber is best used for wavelengths of 1310nm and 1550nm. The difference between the wavelength of 1300nm and 1310nm is only in the customary name. Lasers and light-emitting diodes are also used for light propagation in optical fibers. Lasers are longer than single-mode devices with wavelengths of 1310nm or 1550nm, while light-emitting diodes are used for multimode devices with wavelengths of 850nm or 1300nm.
Why choose these wavelengths?
As mentioned earlier, the most commonly used wavelengths in optical fibers are 850nm, 1300nm and 1550nm. But why do we choose these three wavelengths of light? It is because the optical signals of these three wavelengths have the least loss when transmitted in the optical fiber.Therefore they are most suitable as available light sources for transmission in optical fibers.The loss of glass fiber mainly comes from two aspects: absorption loss and scattering loss.Absorption loss mainly occurs at a few specific wavelengths that we call “water bands”, mainly due to the absorption of trace water droplets in the glass material. The scattering is mainly caused by the rebound of atoms and molecules on the glass. Long wave scattering is much smaller, this is the main function of wavelength.
In conclusion
After reading this article, you may have some basic understanding of the wavelengths used in optical fibers. Because the wavelength loss of 850nm, 1300nm and 1550nm is relatively low, they are the best choice for optical fiber communication.
Post time:
Jan-20-2021
