Fiber Hope trunk cable communication systems

As we all know, the quality of the transmission medium in integrated wiring is very important to the entire project. This is not only the service life of the integrated wiring project, but also the guarantee of its quality and performance. People are often keen to use optical fiber cables as long-distance transmission media because optical fiber cables have the advantages of strong resistance to electromagnetic interference, low signal attenuation, large capacity, light weight, small size, and long transmission distance.Tip 1. Choose fiber optic cables based on materialsMaterials used in optical cables and production processes The selection of optical cable materials is key to the service life of optical cables. The manufacturing process is an important link that affects the quality of optical cables. Products with stable processes and excellent quality are basically not included in the optical fiber additional loss in the entire process of optical cable production. ≤0.01dB/km is the basic data to measure the manufacturer’s optical cable manufacturing process level. .Tip 2: Choose fiber optic cables based on the number of coresThe structures of different types of optical cables can be selected according to the number of cores, which can be divided into central bundle tube type, layer strand type, skeleton type and ribbon type. The structures are different for different uses. Users can put forward corresponding requirements according to the line conditions. Generally, those with less than 12 cores adopt the central bundled tube type. The central bundled tube type has a simple process and low cost, and is competitive in overhead laying or branch trunk line networks with good pipeline protection. Layer-stranded optical cables use centrally placed steel strands or single-stranded optical cables. Reinforced by a steel wire, SZ continuous synthetic cable is used, and the number of fibers in the cable can reach 144 cores.Tip 3: Choose fiber optic cables based on usageChoose the corresponding optical cable according to the purpose. Depending on the purpose, optical cables can be divided into aerial optical cables, direct buried optical cables, submarine optical cables and metal-free optical cables. Aerial optical cables require high strength and a small temperature difference coefficient; direct-buried optical cables require good burial resistance, pressure resistance, moisture resistance, moisture resistance, and chemical erosion resistance; pipeline optical cables and submarine optical cables require water pressure resistance, tension resistance, and good waterproof properties; none Metal optical cables can be erected together with high-voltage lines. The insulation must be good. Although there is no iron core to strengthen the cable, it must have a certain tensile strength.Fiber hope fiber optic cable and patch cord manufacturers can provide high-quality fiber optic cables, fiber patch cords, fiber optic cable clamp, welcome to inquiry!

1. What is the testing principle of optical time domain reflectometer (OTDR)? What is the function?Answer: OTDR is based on the principle of backscattering and Fresnel reflection of light. It uses the backscattered light generated when light propagates in the optical fiber to obtain attenuation information. It can be used to measure fiber attenuation, joint loss, fiber fault point location and Understanding the loss distribution along the length of optical fiber is an indispensable tool in optical cable construction, maintenance and monitoring. Its main index parameters include: dynamic range, sensitivity, resolution, measurement time and blind zone, etc.2. What does “1310nm” or “1550nm” in common light test instruments refer to?Answer: It refers to the wavelength of the optical signal. The wavelength range used in optical fiber communication is in the near-infrared region, with wavelengths between 800nm and 1700nm. It is often divided into short wavelength band and long wavelength band, the former refers to the wavelength of 850nm, and the latter refers to 1310nm and 1550nm.The working wavelength of optical fiber communication is in the near-infrared region, and the bands are:O-band: 1260nm to 1310nmE-band: 1360nm to 1460nmS-band: 1460nm to 1530nmC-band: 1535nm to 1565nmL band: 1565nm to 1625nmU-band: 1640nm to 1675nmSingle-mode fiber usually operates at 1310nm, 1550nm and 1625nm.3. Among currently available commercial optical fibers, what wavelength of light has the smallest dispersion? What wavelength of light has the least loss?Answer: Light with a wavelength of 1310nm has minimum dispersion, and light with a wavelength of 1550nm has minimum loss.4. How are optical fibers classified according to the different modes of light waves transmitted in optical fibers?Answer: It can be divided into single-mode fiber and multi-mode fiber. The core diameter of single-mode optical fiber is approximately between 1 and 10 μm. At a given operating wavelength, it only transmits a single fundamental mode and is suitable for large-capacity long-distance communication systems. Multimode optical fiber can transmit multiple modes of light waves, with a core diameter of approximately 50 to 60 μm, and its transmission performance is worse than that of single-mode optical fiber.5. Optical fiber connectors have two most basic performance parameters. What are they?Answer: Optical fiber connectors are commonly known as unions. For the optical performance requirements of single-fiber connectors, the focus is on the two most basic performance parameters of insertion loss and return loss.6. How many types of commonly used optical fiber connectors are there?Answer: According to different classification methods, fiber optic connectors can be divided into different types.According to different transmission media, they can be divided into single-mode optical fiber connectors and multi-mode optical fiber connectors;According to different structures, it can be divided into various types such as FC, SC, ST, D4, DIN, Biconic, MU, LC, MT, etc.; according to the pin end face of the connector, it can be divided into FC, PC (UPC) and APC.Commonly used optical fiber connectors: FC/PC type optical fiber connector, SC type optical fiber connector, LC type optical fiber connector.7. What are the connection devices for optical fiber?1) Optical fiber splicing2) Optical fiber connectorfiber optic adapterPC/UPC/APC fiber cross sectionThe cross-sections of fiber optic connectors should be divided into PC, UPC, and APC.PC and UPC are optical fiber microsphere end faces that are parallel to the end face of the ceramic body. The industry standard return losses are -35dB and -50dB respectively.The APC section has an 8-degree tilt angle. In order to reduce reflections, the industry standard return loss is -60dB.8. What does an optocoupler mean?Fiber optic coupler (Coupler), also known as splitter (Splitter), is a component that splits optical signals from one optical fiber to multiple optical fibers.Couplers are bidirectional passive devices, and their basic forms include tree and star.9. What are the main optical fibers currently used in transmission network construction?Answer: There are three main types, namely G.652 conventional single-mode fiber, G.653 dispersion-shifted single-mode fiber and G.655 non-zero dispersion-shifted fiber.10. 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 components, such as couplers and optical splitters.Fiber hope fiber optic cable and patch cord manufacturers can provide high-quality fiber optic cables, fiber patch cords, fiber optic cable clamp, welcome to inquiry!

1. What are the components of optical fiber?Answer: Optical fiber consists of two basic parts: a core made of transparent optical materials and a cladding and coating layer.2. What are the basic parameters that describe the transmission characteristics of optical fiber lines?Answer: Including loss, dispersion, bandwidth, cut-off wavelength, mode field diameter, etc.3. What are the most common optical cable structures?Answer: There are two types: layered type and skeleton type.4. What does an optical cable mainly consist of?Answer: Mainly composed of: fiber core, fiber optic grease, sheath material, PBT (polybutylene terephthalate) and other materials.5. What does the armoring of optical cables mean?Answer: It refers to the protective components (usually steel wire or steel strip) used in special-purpose optical cables (such as submarine optical cables, etc.). The armor is attached to the inner jacket of the fiber optic cable.6. What are the causes of fiber attenuation?Answer: The optical power in the optical fiber gradually decreases along the vertical axis. Optical power reduction is related to wavelength. In optical fiber links, the main reasons for optical power reduction are scattering, absorption, and optical power loss caused by connectors and fusion splices. The unit of attenuation is dB.Causes: There are many reasons for fiber attenuation, mainly including: absorption attenuation, including impurity absorption and intrinsic absorption; scattering attenuation, including linear scattering, nonlinear scattering and structurally incomplete scattering, etc.; other attenuation, including micro-bending attenuation, etc. . The most important of these is attenuation caused by impurity absorption.7. What is the bandwidth of optical fiber related to?Answer: The bandwidth of optical fiber refers to the modulation frequency when the amplitude of optical power is reduced by 50% or 3dB from the amplitude of zero frequency in the transfer function of optical fiber. The bandwidth of an optical fiber is approximately inversely proportional to its length, and the product of the bandwidth length is a constant.The phenomenon of light pulse broadening in optical fibers caused by different group velocities of different wavelengths in the spectral components of the light source.8. How to describe the dispersion characteristics of signals propagating in optical fibers?Answer: It can be described by three physical quantities: pulse broadening, fiber bandwidth, and fiber dispersion coefficient.9. What is the cut-off wavelength?Answer: It refers to the shortest wavelength that can only transmit the fundamental mode in the optical fiber. For single-mode fiber, its cutoff wavelength must be shorter than the wavelength of the transmitted light.10. What impact does the dispersion of optical fibers have on the performance of optical fiber communication systems?Answer: The dispersion of optical fiber will cause the light pulse to broaden during transmission in the optical fiber. It affects the bit error rate, the length of the transmission distance, and the system rate.Fiber hope fiber optic cable and patch cord manufacturers can provide high-quality fiber optic cables,  fiber patch cords, fiber optic cable clamp, welcome to inquiry!

1. Types and specifications of optical fiber(1) Fiber type/category:Fiber is mainly divided into two categories, with three classification methods.1) Classification of transmission mode (transmission point modulus) of light in optical fiber:Divided into Single Mode Fiber and Multi Mode Fiber.Single -mode fiber:The central glass core is thinner (the core diameter is generally 9 or 10 μm), and only one mode of light can be passed. Therefore, the color of the models is very small and suitable for remote communication, but its color color scattered the main role. In this way, the single -mode fiber has high requirements for the width and stability of the light source. EssenceThe diameter of the core of the single -mode fiber is very small. In the given working wavelength, it can only be transmitted in a single mode, the transmission frequency bandwidth, and the transmission capacity is large.Multi -mode fiber:The central glass core is thicker (50 or 62.5 μm), which can pass the light of various modes. However, the color scattered between its models is large, which limits the frequency of transmitting digital signals, and it will be more serious with the increase of distance. For example: The optical fiber of 600MB/KM is only 300MB bandwidth at 2km. Therefore, the distance between the multi -mode fiber transmission is relatively close, usually only a few kilometers.Multi -mode optical fiber is a fiber that can be transmitted by multiple modes at the same time on a given working wavelength. Compared with single -mode optical fiber, multi -mode fiber transmission performance is poor.2) Classification according to the distribution of refractive index:The refractive index distribution fiber can be divided into jump -type fiber (also known as mutant fiber) and gradient fiber (also known as gradient fiber).Mutation type: The refractive index from the optical fiber center core to the glass bag is mutated. The refractive index and the refractive index of the jump fiber fiber core are a constant.At the interface of the core and protective layer, the refractive index changes in step type. The cost is low, and the color of the mold is scattered. Suitable for short -distance and low speed communication, such as: industrial control. However, because the single -mode optical fiber is very small, the single -mode fiber uses a mutant type. 　Gradient fiber: The refractive index of the gradient fiber core is reduced as the radius increases as the radius is reduced, and the refractive index at the junction of the core and the protective layer is reduced to the protective layer. The change of refractive index of the core is similar to the parabolic line.The refractive index of the optical fiber center core to the glass bag is gradually becoming smaller, which can spread high -mold light according to sine forms. This can reduce the scattering of the mold, increase the bandwidth of the fiber, and increase the transmission distance. Gradient fiber.3) Classification according to the best transmission frequency window:Conventional single -mode fiber and color scattered displacement single -mode fiber. 　With the advancement of optical fiber communication technology, the rate of optical fiber communication is higher and higher, and the distance is getting longer. The fiber communication system rate and non -vocabulary distance are the scattered bandwidth and attenuation of the fiber. So change the step multi -mode fiber to gradient multi -mode optical fiber, that is, the multi -mode fiber is evolved into a single -mode fiber. Later, the single -mode optical fiber changed various structured changes, derived the single -mode fiber of different varieties.Color scattered color scattered fiber optic fiberFor example: 1310NM zero -color scattered single -mode fiber zero -color scattered single -mode single modular optical fiber; 1550nm single -mode fiber has zero -colored dispersion splitted splitted splitted split -type single -mode fiber, zero -color scattered point near 1310Nm, zero -color scattered point, zero -color scattering point near 1310Nm. However, the attenuation of the 1550Nm window was further reduced, and the anti -micro -curved and bending characteristics were further improved.Therefore, according to this, you can think that the single -mode fiber is divided into two types:Conventional type: Also known as standard single -mode fiber (SMF). The optimization frequency of optical fiber production manufacturers is the optimization frequency of fiber transmission on a single wave of light, such as 1310Nm. 　　Color scattered displacement type: color scattered displacement optical fiber (DSF), optical fiber manufacturers optimize the frequency of optical fiber transmission on two wavelengths of light, such as: 1310Nm and 1550Nm. 　In addition, the color scattered displacement fiber includes the color of the color scattered displacement fiber (DSF) and the non -zero -color dispersion position (NZDSF). Non -zero -color dispersion displacement optical fiber (NZDSF) has a small positive or negative color scattered in 1550nm to reduce the impact of non -linear effects in optical fibers.What needs to be added is:Two types of single -mode fiber that have been installed as a network link, that is, zero -color loose single -mold fiber (SMF) and zero -color loose dispersion optical fiber (DSF) at 1.55 at 1.55 are needed to transmit a higher bit rate. Upgrade these systems and use EDFA in the 1.55 working area. Compensate the optical fiber (DF ~ CF) with a scattering and dispersion to compensate the SMF color scattered and scattered sloping rate at the same time. You can complete the combination of SMF and DFCF in the high -bit rate transmission of the WDM and/(or) TDM system (currently in the experimental stage).Although the absolute value of the common DSF is very small, the DSF has a positive color scattered slope. The use of color scattered slope to compensate the optical fiber (DSCF) for the existing DSF system, which must make the negative color scatter slash of these systems in the working wavelength have a small color scatter value. Therefore, in order to effectively reduce FWM, some companies in the industry have developed several DSFs with different zero -color scattered wavelengths. For each DSF optical fiber, optimized DSCFs need to be developed to optimize the design W refractive index distribution structure. It is understood that the DSCF bandwidth flat area has reached 30nm.(2) Common optical fiber specifications:Single mode: 8/125 μm, 9/125 μm, 10/125 μmMulti -mode: 50/125 μm, European Standard62.5/125 μm, US standardsIndustry, medical and low -speed networks: 100/140 μm, 200/230 μmPlastic: 98/1000 μm, for car control.2. Types of optical cables(1) The laying method is divided into: self -supported overhead light cables, pipeline optical cables, armor land buried optical cables and submarine optical cables. 　　(2) According to the structure of the optical cable, there are: beam tube -type optical cables, layer twisted optical cables, tight -hug -type optical cables, band -type optical cables, non -metal optical cables and branches of optical cables. 　　(3) The use of optical cables, short -distance outdoor optical cables, mixed optical cables and building optical cables are divided into use: long -distance communication. 　　(4) Classification according to the location: indoor optical cable, outdoor optical cable.