{"id":11221,"date":"2025-08-20T17:29:19","date_gmt":"2025-08-20T09:29:19","guid":{"rendered":"https:\/\/ascentoptics.com\/blog\/?p=11221"},"modified":"2025-08-20T17:29:19","modified_gmt":"2025-08-20T09:29:19","slug":"liquid-cooled-optical-transceivers-for-800g-1-6t","status":"publish","type":"post","link":"https:\/\/ascentoptics.com\/blog\/liquid-cooled-optical-transceivers-for-800g-1-6t\/","title":{"rendered":"Liquid-Cooled Optical Transceivers for 800G\/1.6T"},"content":{"rendered":"

With the rapid development of 400G, 800G, and even 1.6T optical modules<\/a>, the power consumption of individual modules continues to rise, making traditional air cooling methods insufficient to meet the heat dissipation demands of high-density data centers and AI clusters. Liquid cooling technology, leveraging its higher thermal conductivity efficiency and energy-saving advantages, has been introduced into the optical module field, becoming a key direction for addressing the bottleneck of high-power heat dissipation. It not only effectively reduces energy consumption and PUE but also aligns with the development trends of green data centers.<\/p>\n

Iteration of Cooling Solutions Driven by Enhanced Integration in Data Centers: By horizontally comparing the networking trends of current mainstream GPU vendors, we can observe that whether it is NVLink, UALink, SUE, RoCE, or CM384, the core concept of their networking is to reduce nodes and achieve more extensive low-latency connections. The iteration of GPU connection solutions is continuously increasing the integration requirements for data centers.<\/p>\n

Traditional air-cooling heat dissipation schemes cannot satisfy the economic and integration demands of computing power centers primarily based on accelerator cards, while liquid cooling solutions\u2014whether cold-plate, spray, or immersion liquid cooling\u2014provide better high-integration solutions.<\/p>\n

 <\/p>\n

Core Concept of Liquid-Cooled Optical Transceivers<\/strong><\/h2>\n

A liquid-cooled optical transceiver is a high-speed module that incorporates liquid cooling technologies (such as cold plates or microchannels) into traditional optical modules to achieve efficient heat dissipation. As optical interconnect speeds evolve from 400G to 800G and even 1.6T, the power consumption of a single module has exceeded 15W, making conventional air cooling increasingly insufficient for high-density environments.<\/p>\n

With its much higher specific heat capacity and thermal conductivity compared to air, liquid cooling can rapidly remove heat, significantly improving heat dissipation efficiency. This prevents performance degradation or failures caused by overheating, while enabling higher power density and port density deployment. The core concept of liquid-cooled optical modules is the integration of liquid cooling technology with optical transceivers to achieve efficient thermal management, thereby enhancing the stability and lifespan of high-performance optical communication\u00a0equipment.<\/p>\n

 <\/p>\n

Liquid Cooling Technology<\/b><\/strong><\/p>\n

\"Classification
Classification of Liquid Cooling Technologies<\/figcaption><\/figure>\n

 <\/p>\n

Liquid cooling technology uses liquids (such as water or other thermally conductive fluids) as the cooling medium, removing the large amount of heat generated during the operation of optical transceivers through continuous circulation. Compared with traditional air cooling, liquid cooling offers much higher thermal conductivity, effectively reducing module temperature and making it ideal for high-power, high-density applications.<\/p>\n

Depending on the contact method between the cooling liquid and the heat-generating device, liquid cooling can be divided into indirect and direct approaches:<\/p>\n

Indirect Liquid Cooling:<\/b><\/strong>\u00a0The cooling liquid does not directly contact the heat source. A typical example is the cold plate design, where heat is transferred from the device surface to the coolant via a thermal interface.<\/p>\n

Direct Liquid Cooling:<\/b><\/strong>\u00a0The cooling liquid directly contacts the heat source. This includes immersion cooling and spray cooling. Immersion cooling can be further divided into single-phase immersion and two-phase (phase-change) immersion, depending on whether the cooling medium undergoes a phase change during operation.<\/p>\n

 <\/p>\n

Advantages and Challenges of Liquid-Cooled Optical Modules<\/strong><\/h2>\n

Compared with traditional air cooling, liquid-cooled optical modules offer significantly higher thermal efficiency, enabling 400G and 800G high-speed modules to operate stably in data centers, 5G networks, and supercomputing environments that demand high density and power. Key advantages include:<\/p>\n