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Wednesday, September 18, 2019 8:04 am - 11:04 am
No.192,Beixing Road,Mazhu Town,Yuyao City,Zhejiang Province,P.R.C
No.192,Beixing Road,Mazhu Town,Yuyao City,Zhejiang Province,P.R.C
Yuyao
315450
China
Fiber Loss In recent years, fiber optic communication has been widely used in many fields. An important issue in achieving fiber-optic communication is to reduce the loss of the fiber as much as possible. The so-called loss refers to the attenuation per unit length of the fiber, and the unit is dB/km. The fiber loss has a direct impact on the transmission distance or the distance between the relay stations. Therefore, understanding and reducing the loss of the fiber has great practical significance for fiber-optic communication. Below, the DOME Fiber Closure manufacturer will take a look at it:
First, the absorption loss of the fiber
This is caused by the absorption of light energy by fiber materials and impurities. They consume light energy in the form of heat energy in the fiber, which is an important loss in fiber loss. The absorption loss includes the following:
1. Intrinsic Absorption Loss This is the loss due to the inherent absorption of the material. It has two frequency bands, one in the near-infrared region of 8 to 12 μm, and the intrinsic absorption of this band is due to vibration. The intrinsic absorption band of another substance is in the ultraviolet range. When the absorption is strong, its tail will be dragged into the 0.7-1.1 μm band.
2. Absorption losses due to dopants and impurity ions Fiber materials contain transition metals such as iron, copper, chromium, etc., which have their own absorption peaks and absorption bands and vary with their valence states. The loss of fiber caused by the absorption of transition metal ions depends on their concentration. In addition, absorption of OH- also causes absorption loss, the basic absorption peak of OH- is around 2.7 μm, and the absorption band is in the range of 0.5 to 1.0 μm. For pure silica fibers, the effects of impurities caused by impurities can be ignored.
3. Atomic Defect Absorption Loss Due to the heat or strong radiation, the fiber material is excited to generate atomic defects, which cause absorption of light and loss, but in general, this effect is small.
Second, the scattering loss of the fiber
The scattering inside the fiber reduces the power transmitted and generates losses. The most important of the scattering is Rayleigh scattering, which is caused by changes in density and composition inside the fiber material.
During the heating process of the optical fiber material, due to the thermal turbulence, the compressibility of the atoms is not uniform, the density of the material is not uniform, and the refractive index is not uniform. This unevenness is fixed during the cooling process and its size is smaller than the wavelength of the light wave. When the light encounters these light-wavelengths, which are smaller than the wavelength of the light wave, and the uneven material with random fluctuations, the transmission direction is changed, scattering occurs, and loss is caused. In addition, uneven concentration of oxides contained in the optical fiber and uneven doping may cause scattering and loss.
Third, the waveguide scattering loss
This is due to the random distortion or coarse scattering of the interface, which is actually a mode transition or mode coupling caused by surface distortion or roughness. One mode produces other modes of transmission and radiation patterns due to the fluctuations in the interface. Due to the different modes of attenuation transmitted in the optical fiber, in the long-distance mode conversion process, the mode with small attenuation becomes a mode with large attenuation, and after continuous transformation and inverse transformation, although the loss of each mode is balanced, The pattern overall produces additional losses, ie additional losses due to mode conversion, which is the waveguide scattering loss. To reduce this loss, it is necessary to improve the fiber manufacturing process. For a well-drawn or high-quality fiber, this loss can basically be ignored.
Fourth, the radiation loss caused by fiber bending
The fiber is soft and can be bent, but after bending to a certain extent, although the fiber can guide light, it will change the transmission path of light. The transmission mode is converted into a radiation mode, so that a part of the light energy penetrates into the cladding layer or passes through the cladding layer to become a radiation mode and is leaked outward, thereby causing loss. When the bending radius is larger than 5 to 10 cm, the loss caused by the bending is negligible.
information about DOME Fiber Closure : https://www.greentelftth.com/product/fiber-optical...
First, the absorption loss of the fiber
This is caused by the absorption of light energy by fiber materials and impurities. They consume light energy in the form of heat energy in the fiber, which is an important loss in fiber loss. The absorption loss includes the following:
1. Intrinsic Absorption Loss This is the loss due to the inherent absorption of the material. It has two frequency bands, one in the near-infrared region of 8 to 12 μm, and the intrinsic absorption of this band is due to vibration. The intrinsic absorption band of another substance is in the ultraviolet range. When the absorption is strong, its tail will be dragged into the 0.7-1.1 μm band.
2. Absorption losses due to dopants and impurity ions Fiber materials contain transition metals such as iron, copper, chromium, etc., which have their own absorption peaks and absorption bands and vary with their valence states. The loss of fiber caused by the absorption of transition metal ions depends on their concentration. In addition, absorption of OH- also causes absorption loss, the basic absorption peak of OH- is around 2.7 μm, and the absorption band is in the range of 0.5 to 1.0 μm. For pure silica fibers, the effects of impurities caused by impurities can be ignored.
3. Atomic Defect Absorption Loss Due to the heat or strong radiation, the fiber material is excited to generate atomic defects, which cause absorption of light and loss, but in general, this effect is small.
Second, the scattering loss of the fiber
The scattering inside the fiber reduces the power transmitted and generates losses. The most important of the scattering is Rayleigh scattering, which is caused by changes in density and composition inside the fiber material.
During the heating process of the optical fiber material, due to the thermal turbulence, the compressibility of the atoms is not uniform, the density of the material is not uniform, and the refractive index is not uniform. This unevenness is fixed during the cooling process and its size is smaller than the wavelength of the light wave. When the light encounters these light-wavelengths, which are smaller than the wavelength of the light wave, and the uneven material with random fluctuations, the transmission direction is changed, scattering occurs, and loss is caused. In addition, uneven concentration of oxides contained in the optical fiber and uneven doping may cause scattering and loss.
Third, the waveguide scattering loss
This is due to the random distortion or coarse scattering of the interface, which is actually a mode transition or mode coupling caused by surface distortion or roughness. One mode produces other modes of transmission and radiation patterns due to the fluctuations in the interface. Due to the different modes of attenuation transmitted in the optical fiber, in the long-distance mode conversion process, the mode with small attenuation becomes a mode with large attenuation, and after continuous transformation and inverse transformation, although the loss of each mode is balanced, The pattern overall produces additional losses, ie additional losses due to mode conversion, which is the waveguide scattering loss. To reduce this loss, it is necessary to improve the fiber manufacturing process. For a well-drawn or high-quality fiber, this loss can basically be ignored.
Fourth, the radiation loss caused by fiber bending
The fiber is soft and can be bent, but after bending to a certain extent, although the fiber can guide light, it will change the transmission path of light. The transmission mode is converted into a radiation mode, so that a part of the light energy penetrates into the cladding layer or passes through the cladding layer to become a radiation mode and is leaked outward, thereby causing loss. When the bending radius is larger than 5 to 10 cm, the loss caused by the bending is negligible.
information about DOME Fiber Closure : https://www.greentelftth.com/product/fiber-optical...