In the era of 5G, cloud computing, and big data, enterprise networks have an increasing demand for high-speed and long-distance data transmission. Under such circumstances, the QSFP28 100G 80KM optical module, with its transmission rate of up to 100Gbps and a range of 80 kilometers, has become a key device for interconnecting backbone networks and transmitting data between data centers. However, with a wide variety of optical module brands on the market and complex parameter annotations, it is easy to make a wrong choice. This article will provide a detailed interpretation of how to select a high-cost-performance optical module from five key aspects.

I. Core Performance Parameters: The Key Indicators for Measuring Quality

1. Wavelength and Fiber Compatibility
   The QSFP28 100G 80KM optical module generally uses a wavelength of 1550nm. This wavelength has the lowest loss when transmitted through single-mode fiber, ensuring stable long-distance transmission. During the purchasing process, it is essential to confirm the type of fiber being used. G.652D single-mode fiber is the most widely used and is suitable for most scenarios. In contrast, G.657A fiber has stronger anti-bending performance, making it particularly suitable for environments with limited space and complex cabling. If the wavelength of the optical module does not match the fiber, it may lead to severe signal attenuation and a significant reduction in the actual transmission distance.
2. Transmit Optical Power and Receive Sensitivity
   Transmit optical power determines the initial strength of the signal, while receive sensitivity reflects the optical module's ability to capture weak signals. For example, in an 80-kilometer transmission scenario, the transmit optical power should generally be between -3dBm and 3dBm, and the receive sensitivity should be better than -21dBm. If the transmit power is too low, the signal may gradually disappear during long-distance transmission. Insufficient receive sensitivity can lead to an increase in bit error rate. It is recommended to choose optical modules with some parameter redundancy to better cope with various complex usage environments.
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II. Compatibility: Ensuring Seamless Device Integration

Different brands of switches and routers have varying levels of compatibility with optical modules. Although mainstream equipment vendors like Cisco, Huawei, and Juniper all follow the MSA (Multi-Source Agreement) standard, they also incorporate some proprietary protocols. Before purchasing an optical module, it is crucial to check the compatibility list published by the equipment vendor or request a compatibility test report from the supplier. For example, some third-party optical modules may not be recognized by Huawei equipment. Conducting tests in advance can effectively avoid over 90% of compatibility issues.

III. Thermal Design: Ensuring Long-Term Stable Operation

The 100G high-speed optical module generates a significant amount of heat during operation. Poor heat dissipation can lead to performance degradation and even damage to the optical module. High-quality optical modules typically use metal housings for heat dissipation, combined with a precise PCB layout to quickly conduct heat away. Additionally, some optical modules are equipped with intelligent temperature control chips that can automatically adjust working parameters based on temperature. It is recommended to choose optical modules with metal housings that have passed thermal certification (such as FCC, CE), especially in high-temperature environments like data centers, where such products are more suitable.

IV. Certification: A Strong Proof of Quality