Micro Fiber optic cable Wholesale

Q1: What is optical fiber? Is there a difference between optical fiber and fiber optic cable?Answer: Optical fiber is a fine and flexible medium that transmits light beams. It is the abbreviation of optical fiber. The most commonly used product of optical fiber used in integrated wiring is the glass core for light transmission. The core is usually a double-layer concentric cylinder made of quartz glass with a small cross-sectional area, which is brittle and easy to break, so an external protective layer is required. Optical fiber is used in idioms far beyond its own meaning. It can represent either the fiber core, the fiber optic cable, the fiber optic cabling system or even the fiber optic communication system. However, in order to accurately define the products of each part of the optical fiber cabling system, the general optical fiber refers to the core part, and the optical fiber cable is the finished cable composed of the optical fiber as the transmission unit.Q2: What are the classifications of optical cables?Answer: According to the type of fiber core, it can be divided into: single-mode optical cable and multi-mode optical cable according to the laying method: self-supporting overhead optical cable, pipeline optical cable, armored buried optical cable and submarine optical cable. According to the optical cable structure, it is divided into: bundled optical cable, layered optical cable, skeleton optical cable, tightly hugging optical cable, ribbon optical cable, non-metallic optical cable and branchable optical cable. According to the application: long-distance communication optical cable, short-distance outdoor optical cable, hybrid optical cable and optical cable for building Fiber optic cables and fiber optic cables for use in buildingsQ3: What is the difference between multimode fiber and single mode fiber?Answer: Multimode fiber: a fiber that can propagate electromagnetic waves in multiple modes, while a single-mode fiber can only transmit a single fundamental mode fiber. Compared with single-mode fiber, multimode fiber has a larger core, but the dispersion is much larger, and the transmission capacity Smaller and shorter transmission distance.Q4: What is the transmission distance of the optical cable in the national standard?Answer: It is stipulated in the GB50311 national standard that the transmission distance of multi-mode optical cable is 2km, and the transmission distance of single-mode optical cable is 3km. Note here that 2km and 3km are the limits specified in the GB50311 standard range, not the medium limit. Generally speaking, the use of multi-mode optical cable in communication is within 500 meters, while the non-relay communication distance of single-mode optical cable is generally 60 km.Fiber hope fiber optic cable and patch cord manufacturers can provide high-quality fiber optic cables, fiber pigtails, fiber patch cords, single-mode multi-mode fiber, welcome to inquiry!

1. Optical fiber scattering lossThe scattering inside the fiber will reduce the transmitted power and cause loss. The most important of 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 disturbance, the compressibility of the atoms is not uniform, the density of the material is not uniform, and the refractive index is not uniform. This inhomogeneity is fixed during the cooling process, and its size is smaller than the wavelength of light. When light encounters these non-uniform substances with random fluctuations smaller than the wavelength of the light wave during transmission, it changes the transmission direction, produces scattering, and causes loss. In addition, the uneven concentration of oxides contained in the optical fiber and uneven doping can also cause scattering and loss.2. Waveguide scattering lossThis is scattering due to random distortion or roughness at the interface, and it is actually mode switching or mode coupling caused by surface distortion or roughness. One mode will give rise to other modes of transmission and radiation due to the fluctuation of the interface. Due to the different attenuation of various modes transmitted in the fiber, in the process of long-distance mode conversion, the mode with small attenuation becomes the mode with large attenuation. After continuous transformation and inverse transformation, although the loss of each mode will be balanced, but The mode generally produces additional loss, that is, additional loss due to mode conversion, and this additional loss is the waveguide scattering loss. To reduce this loss, it is necessary to improve the optical fiber manufacturing process. For well-drawn or high-quality fibers, this loss is essentially negligible.3. Radiation loss caused by fiber bendingOptical fibers are flexible and can be bent, but after bending to a certain extent, although optical fibers can guide light, the transmission path of light will change. The transmission mode is converted into a radiation mode, so that a part of the light energy penetrates into the cladding or passes through the cladding as a radiation mode that leaks out and is lost, resulting in loss. When the bending radius is greater than 5~10cm, the loss caused by bending can be ignored.Fiber hope fiber optic cable and patch cord manufacturers can provide high-quality fiber optic cables,fiber pigtails, fiber patch cords, single-mode multi-mode fiber, welcome to inquiry!

1. Classification of fiber lossOptical fiber loss can be roughly divided into the inherent loss of the optical fiber and the additional loss caused by the operating conditions after the optical fiber is made. The specific breakdown is as follows:Fiber loss can be divided into inherent loss and additional loss:Inherent losses include scattering losses, absorption losses, and losses due to imperfect fiber structure.Additional losses include microbending losses, bending losses and splice losses.Among them, the additional loss is artificially caused during the laying process of the optical fiber. In practical applications, it is inevitable to connect the optical fibers one by one, and the optical fiber connection will produce loss. The slight bending, extrusion, and tensile force of the optical fiber will also cause loss. These are losses caused by the conditions of use of the fiber. The main reason for this is that under these conditions, the transmission mode in the fiber core changes. Additional losses can be avoided as much as possible. Below, we only discuss the inherent loss of fiber.Among the inherent losses, scattering loss and absorption loss are determined by the characteristics of the fiber material itself, and the inherent loss caused by different operating wavelengths is also different. It is very important to understand the mechanism of loss and quantitatively analyze the loss caused by various factors for the development of low-loss optical fiber and the rational use of optical fiber.2. Absorption loss of materialsOptical fibers are made of materials that absorb light energy. After the particles in the fiber material absorb the light energy, they vibrate and generate heat, and dissipate the energy, thus resulting in absorption loss. We know that matter is composed of atoms and molecules, and atoms are composed of nuclei and extranuclear electrons. The electrons revolve around the nucleus in a certain orbit. This is just like the earth where we live and the planets such as Venus and Mars all revolve around the sun. Each electron has a certain energy and is in a certain orbit, or each orbit has a certain energy level.Orbitals closer to the nucleus have lower energy levels, and orbitals farther from the nucleus have higher energy levels. The magnitude of this energy level difference between orbitals is called the energy level difference. When an electron transitions from a low energy level to a high energy level, it absorbs the energy of the corresponding level of energy difference.In an optical fiber, when electrons of a certain energy level are irradiated with light of a wavelength corresponding to the energy level difference, electrons located in the orbits of lower energy levels will transition to orbits of higher energy levels. This electron absorbs light energy, resulting in light absorption loss.The basic material for making optical fibers, silicon dioxide (SiO2), itself absorbs light, one is called ultraviolet absorption, and the other is called infrared absorption. At present, optical fiber communication generally only works in the wavelength region of 0.8~1.6μm, so we only discuss the loss in this working region.The absorption peak generated by electronic transition in quartz glass is around 0.1~0.2μm wavelength in the ultraviolet region. As the wavelength increases, its absorption gradually decreases, but the affected area is wide, up to wavelengths above 1 μm. However, UV absorption has little effect on silica fibers operating in the infrared region. For example, in the visible light region of 0.6μm wavelength, the UV absorption can reach 1dB/km, at 0.8μm wavelength it drops to 0.2~0.3dB/km, and at 1.2μm wavelength, it is only about 0.1dB/km.The infrared absorption loss of silica fiber is caused by the molecular vibration of the material in the infrared region. There are several vibration absorption peaks above 2μm.Due to the influence of various doping elements in the fiber, it is impossible for the silica fiber to have a low-loss window in the wavelength band above 2 μm, and the theoretical limit loss at the wavelength of 1.85 μm is 1dB/km.Through research, it is also found that there are some "destructive molecules" in quartz glass, mainly some harmful transition metal impurities, such as copper, iron, chromium, manganese and so on. Under the irradiation of light, these "bad guys" greedily absorb light energy and jump around, causing the loss of light energy. Eliminating the "troubling molecules" and chemically purifying the material from which the fiber is made can greatly reduce losses.Fiber hope fiber optic cable and patch cord manufacturers can provide high-quality fiber optic cables,fiber pigtails, fiber patch cords, single-mode multi-mode fiber, welcome to inquiry!

1. What is the nonlinearity of fiber?Answer: It means that when the optical power of the incoming fiber exceeds a certain value, the refractive index of the optical fiber will be nonlinearly related to the optical power, and Raman scattering and Brillouin scattering will occur, which will change the frequency of the incident light.2. What effect will fiber nonlinearity have on transmission?A: Non-linear effects will cause some additional losses and disturbances, degrading the performance of the system. WDM systems have high optical power and travel long distances along the fiber, thus producing nonlinear distortion. There are two types of nonlinear distortion: stimulated scattering and nonlinear refraction. Among them, stimulated scattering includes Raman scattering and Brillouin scattering. The above two kinds of scattering reduce the energy of incident light and cause loss. It can be ignored when the input fiber power is small.3. What is PON (Passive Optical Network)?Answer: PON is an optical fiber loop optical network in the local user access network, based on passive optical devices, such as couplers and optical splittersVarious causes of fiber attenuationThe main factors that cause fiber attenuation are: intrinsic, bending, extrusion, impurities, non-uniformity and butt joint.Intrinsic: It is the inherent loss of the fiber, including: Rayleigh scattering, intrinsic absorption, etc.Bending: When the fiber is bent, part of the light in the fiber will be lost due to scattering, resulting in loss.Squeeze: Loss caused by tiny bends in an optical fiber when it is squeezed.Impurities: Losses caused by impurities in the fiber absorbing and scattering light propagating in the fiber.Non-uniformity: Loss caused by non-uniform refractive index of the fiber material.Docking: The loss generated when the optical fiber is docked, such as: non-axial (the coaxiality of single-mode fiber is required to be less than 0.8 μm), the end face is not perpendicular to the axis, the end face is not flat, the butt core diameter does not match, and the welding quality is poor.When light enters from one end of an optical fiber and exits from the other end, the intensity of the light decreases. This means that after the optical signal propagates through the fiber, the light energy is partially attenuated. This means that there is some substance in the fiber or for some reason that blocks the passage of the light signal. This is the transmission loss of the fiber. Only by reducing the fiber loss can the optical signal be made unimpeded.Fiber hope fiber optic cable and patch cord manufacturers can provide high-quality fiber optic cables, fiber pigtails, fiber patch cords, single-mode multi-mode fiber, welcome to inquiry!