With the rapid development of the Internet of Things, big data, and cloud computing technology, the amount of transmission required for information exchange has shown an explosive growth. Among them, semiconductor lasers, as the basic component supporting the development of optical communication, are constantly being optimized to meet the needs of modern communication.
Compared to 4G base stations, 5G base stations have undergone some changes, evolving from the bipolar structure of BBU and RRU in 4G to the three-level structure of centralized unit (CU), distributed unit (DU), and active antenna processing unit (AAU) in 5G, resulting in three networks: forward, intermediate, and return.
After the concept of 5G was proposed, the demand for optical modules has significantly increased, which is mainly reflected in two aspects. On the one hand, there is a demand for the number of optical modules. In addition to the traditional requirements for forward and backward optical modules, new optical modules need to be added in the intermediate transmission stage; On the other hand, there is a demand for the speed of optical modules. 4G forward transmission and return transmission use 10G optical modules, while 5G forward transmission requires tens of millions of 25G/50G optical modules, while return transmission requires 100G optical modules. In the convergence layer of return transmission, even 200G or 400G optical modules are needed.
According to survey agency data, the construction of 5G carrier network base stations before 2022 is a period of rapid development, and the demand for optical modules is rapidly driven by the construction of carrier networks. It is expected that the total expenditure of 5G networks will be 1400 billion, and the market volume of optical modules is expected to reach 62 billion. It is expected that the investment in optical modules will account for 4.4% of the total expenditure of 5G networks.
At present, the packaging challenges of optoelectronic devices face the following issues: the first is how to design efficient coupling systems and temperature control systems; The second is how to utilize the parasitic effects brought by packaging to compensate for the shortcomings of the chip while the single transistor device is moving towards high speed and large bandwidth; The third issue is how to achieve the feeding of multiple microwave signals in a limited space, as well as complex structural designs such as complete structural transformation and mode field matching, when array devices are developing towards miniaturization and integration.
In short, the opening of the 5G era will stimulate the development of the laser module industry. Based on existing packaging processes and foundations, the development of high bandwidth single tube laser modules and small and highly integrated array laser modules is currently an urgent problem to be solved in the scientific research community and industry chain. For the large-scale deployment of 5G communication, it is necessary to use a large number of 25G and 100G optical modules to meet the requirements of different program optical interface services in different application scenarios for forward and intermediate return networks.
