Optical communication is proliferation. With the continuous progress of society, the way of human's long-distance communication gradually changes from letter to communication. As long as there is a smart phone, video calls and voice calls are very simple for the elderly. With the continuous increase in human demand, traffic has shown explosive growth. Here, the optical fiber comes in handy. It can bring high bandwidth to meet the needs of the public. All the optical modules are composed of two parts: the receiver and the transmitter. In this way, the photoelectric conversion and the electro-optic conversion can be performed. In this way, the optical modules (such as the fiber optic splice closure) cannot be separated at both ends of the network. Single-fiber bidirectional optical module selection skills and use of many believe that many people understand that the optical module components are optoelectronic devices, functional circuits and optical interfaces, optoelectronic devices including transmit and receive two parts. The optical module can convert the electrical signal into an optical signal at the transmitting end through photoelectric conversion, and then transmits the optical fiber and then converts the optical signal into an electrical signal at the receiving end. For a long time to come, optical fiber will remain the main medium for global communications. Fiber optic splice closure is also entering every home. Optical fiber transmission has many outstanding advantages such as wide frequency band, low loss, light weight, strong anti-interference ability, high fidelity, and reliable working performance. Although it is still somewhat lacking in military use, there is no problem in civilian use. And with the ultra-low loss, large effective area and other advantages of the emergence of new types of optical fiber. Optical fiber is definitely the best choice for transmitting communications. For example, in the aspect of international communication transmission, submarine optical fiber is more attractive. Compared with satellites, submarine Fiber Optic Splice Closure has many advantages. The submarine cable has a low signal-to-noise ratio and no time delay in communication. The design life of submarine cable is 25 years of continuous operation. Its high quality, low cost, and large capacity transmission methods are increasingly favored by people.