Recently, the sales partner encountered a thorny problem, the customer received the optical module can not be used, after much research to find the reason, the original customer purchased the optical module with a heat sink, and the existing network card slots do not match. What is the difference between the flat top of the optical  transceiver module and the top of the heat sink? In the use of how to choose, follow the editorial below to take a look at it!

I.The difference between the flat top and the heat sink top of the optical module

Flat-top and heatsink top in the optical module usually refers to two different structures in the optoelectronic device:

Flat-top (Flat-top): flat-top structure usually refers to the top structure of the laser or light emitter in the optical module is flat. This design allows light to propagate and focus more easily, facilitating more efficient transmission of optical signals in optical fibers or other transmission media. The flat top design improves the coupling and transmission efficiency of light, and is more common in some high-performance optical communications or optical sensors.

Heatsink-top: A heatsink-top structure usually refers to a laser or optoelectronic device designed with heatsinks on top. These heatsinks are typically used to efficiently dissipate heat to keep the device operating temperature within safe limits. In high power or high density applications, the device may generate a large amount of heat, which needs to be transferred to the surrounding environment through the heatsink to prevent the device from overheating and being damaged. Therefore, heatsink design is critical to the long-term stable operation of optical modules.

II.How to choose between flat tops and heat sink tops for optical modules

With the growth of the transmission rate, the volume of the optical module is gradually miniaturized, the internal requirements of the optical device is also more and more high, to solve the heat dissipation problem is very necessary. Flat top and heat sink top of the optical module have their own advantages, the choice of which is better mainly depends on the transmission rate, interface type, packaging and specific application scenarios and needs.

Transmission distance and rate requirements: If your application requires long-distance and high-speed transmission, the flat-top structure may be more suitable because it is conducive to improving the optical coupling efficiency and transmission efficiency. For short distance or low speed transmission, heat sink top structure can be considered more.

Thermal Management Requirements: If your application has lasers or optoelectronic devices that need to handle a large amount of power or high density energy, then the heatsink top structure may be more important because it facilitates effective heat dissipation, thus maintaining stable module operation and preventing overheating that can lead to degradation of performance or damage. Especially in applications such as high power optical communications or LIDAR, good thermal management is critical.

Cost and complexity: The flat-top version of the optical module has a simple design without an additional heatsink structure because it focuses on light transmission efficiency, while the heatsink-top structure may require a more complex design and manufacturing process to ensure good thermal performance. Therefore, you need to weigh both options when considering cost and complexity.

Environmental conditions: Consider what kind of environmental conditions your application will operate in. If the ambient temperature is high or there is a possibility of being affected by other heat sources, good heat dissipation may be more important.

Reliability and Stability Requirements: If your application has high requirements for the long-term stable operation of the device, it may be more appropriate to choose a heatsink top structure that provides good thermal management.

III.Common Flat-Top and Heatsink-Top Optical Modules and Applications

In the 800G OSFP series, SR8, DR8 and 2FR4 optical modules are designed with a heatsink top to ensure stable operation and efficient heat dissipation during high-speed data transmission. The 400G OSFP SR4 and DR4 modules have a flat-top design, which is suitable for applications with relatively low heat dissipation requirements.

The heatsink-topped optical modules are especially suitable for switch devices that require high thermal efficiency, including Quantum-2 InfiniBand switches and Spectrum-4 Ethernet switches, which process large amounts of data, and the heatsink-topped optical modules provide the necessary thermal management.

Flat-top slots are commonly used in adapters and data processing units (DPUs), such as the ConnectX-7 InfiniBand adapter card and the BlueField-3 DPU, with a flat-top design with a heatsink-topped heatsink to meet the thermal needs of these devices under different operating conditions.

The flat-top version and the heatsink-top version have the same internal structure, but the heatsink-top version is taller due to the inclusion of a heat sink. In terms of transmission power, the heatsink of OSFP optical modules is integrated inside the module housing and has a larger heat dissipation surface area than QSFP-DD optical modules, which optimizes the thermal contact between the heat dissipation components and the heatsink, and the heat dissipation performance is better than that of QSFP-DD optical modules.

Therefore, when choosing an optical module, it is also necessary to consider these factors comprehensively and choose the product that best suits your needs. This issue of the article content ends here, ETU-LINK can provide 400G flat top and with heat sink top optical modules, welcome to inquire about!