Application Scenarios of Optical Transceiver

Oct 21, 2024

The optical transceiver is usually composed of optoelectronic devices, functional circuits and optical interfaces, etc. Optoelectronic devices include two parts: transmitting and receiving. Simply put, the function of an optical transceiver module is to convert electrical signals into optical signals at the transmitting end. After being transmitted through optical fiber, the optical signal will be converted into electrical signals the receiving end. According to the working mode of optical fiber, they are divided into single-mode ones and multi-mode ones. The former is suitable for long-distance transmission, while the latter is mostly suitable for short-distance transmission.

Several application scenarios of optical modules

1. Data Center Interconnection
With the rapid development of emerging businesses such as cloud computing, big data and VR, many applications that rely heavily on data centers have exploded. A single data center is overwhelmed and soon faces a shortage of resources. However, due to site and energy supply issues, a single data center cannot simply expand its capacity. At this time, building multiple data centers in the same city or in different places, and forming interconnections and collaborative business support between them has become a new option, thus creating a new scenario, data center interconnection DCI.

More and more companies are undergoing digital transformation, and companies in the same industry need to share and collaborate at the data level, which also prompts data centers of different companies to interconnect with each other.

Data center interconnection scenarios require massive information interaction between data centers. Both the amount of information and the transmission frequency will be larger and denser, and the distance will be farther than that of a single data center, so the advantages of fiber-optic communication stand out.
In addition, data center interconnection scenarios require higher switching equipment speed, lower power consumption and more miniaturization, and one of the core factors that determines whether these performances can be achieved is the optical module.
The continuous growth of data center data traffic, the large-scale and flattening trend between data centers has gradually promoted the development of optical modules to a faster transmission rate. The transmission distance of multi-mode optical fiber is limited by the increase in signal rate, so it will gradually be replaced by single-mode optical fiber in data center interconnection scenarios.

2. Telecommunications market: 5G deployment will greatly increase the demand for optical modules
The 5G network is divided into three parts: access network, bearer network and core network. Among them, the bearer network is generally divided into metropolitan access layer, metropolitan aggregation layer, metropolitan core layer/provincial trunk line, and the fronthaul and mid-haul functions of real-line 5G services. Compared with 4G, 5G has undergone some changes compared to 4G base stations, adding the mid-haul link, which has opened up the market for mid-haul optical modules. In addition, the optical modules used in the fronthaul and backhaul links of 4G do not have such high requirements for transmission rate, and 10G optical modules are used. However, the high bandwidth, low latency, and large connection characteristics of 5G wireless communication put forward higher requirements for the functions and performance of optical modules. The future demand and requirements for 25G, 50G, and even more 100G optical modules will be greatly improved.

3. Passive wavelength division multiplexing
The core principle of wavelength division multiplexing technology is to use WDM technology to couple optical signals with different wavelengths and carrying a series of information into a beam, and transmit them in an optical fiber to achieve transmission between services. These optical signals of different wavelengths can be separated at the receiving end. At present, many applications are used in campus network deployment. While ensuring high-speed and low-latency transmission, it can also greatly improve the utilization rate of trunk optical cables. At the same time, the passive combiner can greatly reduce the operation and maintenance of the network. Passive wavelength division consists of color optical modules (usually coarse wavelength division modules, dense wavelength division modules are called color optical modules, usually using dual-fiber modules) and passive devices.
The transmit and receive wavelengths in the color optical module indicators will have a nominal center frequency/center wavelength; the transmit and receive wavelengths of the gray optical module are in a wider range and have no center wavelength. Therefore, it can be judged by whether there is a center wavelength in the indicator. Color optical module CWDM is widely used in Gigabit Ethernet and point-to-point networks, while DWDM modules are mainly used in large network environments such as metropolitan area networks and local area networks.

Optical modules are the core components of optical communications, and their strategic significance is self-evident. In the future, with the acceleration of 5G network construction, the rapid development of cloud computing, and the mass construction of large-scale data centers, 400G-800G will become the main competitive direction of the optical communication industry.

PREV: Since the optical fiber is made of glass, why should it be protected from water? NEXT: Indoor Flexible Armored Cable