How is the undersea fiber optic cable laid and data transmission?

Optical fiber optical communication can not be separated from the contribution of Chinese engineer Gao Kun, he first theorized in 1966 that glass fibers could be used in communications as a medium for light transmission, "The main cause of signal loss is the impurity of the material, not the glass itself," and he was Nobel Prize in Physics in 2009 for his contributions to Fiber-optic communication.

The undersea cable must be surrounded by layers of protective structure. Typical undersea cable structures include: the first layer is an insulating polyethylene layer, the second layer is a polyester film strip or asphalt layer, the third layer is steel strand, the fourth is aluminum waterproof, the fifth is polycarbonate, and the sixth is copper or aluminum tube. This layer can be electrified to power the fiber optic cable repeater, and the voltage often exceeds 10,000 volts, the seventh layer is the paraffin, alkane layer, the eighth layer is the core of the optical signal transmission fiber.

Both Sea and land cables will age and be updated iteratively. Almost every year new cables come into operation around the world. Our country at present in Qingdao, Shanghai, Shantou, Hong Kong and other places have cable landing facilities, up to dozens of cables to communicate with the world. As the infrastructure of the Internet, the cable is being continuously updated and constructed to meet the needs of the reality. For optical transmission, it is recommended to search directly for DWDM technology, through modulation technology from transmission equipment manufacturers (Huawei, ZTE, beacon, Ciena, Nokia, etc.) , the 0 and 1 signals of computer language are multiplexed to light wave for information transmission. Current technology can achieve single-wave 800G or 1.2 t or higher, a pair of fiber transmission 40 ~ 60T. Optical fiber is based on the relevant international standards (G652, G654, etc.) made, the relevant standards are also to serve better transmission capacity, its effective transmission cross-sectional area is generally fixed. Optical fiber is the thin wire of physical existence, there are broadband home of waste optical fiber can be directly opened to see, very thin. Yes, that's right. It's so small, but it can carry 10 terabytes of transmission capacity. The composition of optical fiber can also refer to some of the Baidu Materials, general search DWDM courseware will be involved. In fact, the marine environment does not generally decay. Sea cables in the seabed generally do a good job of protection and waterproof work can actually adapt to the marine environment. Near shore and shallow water will face fishing nets and anchors, the general cable will be double-armored deep-buried way to protect, deep water areas are generally waterproof.