SEOUL & SAN FRANCISCO -- LESSENGERS Inc., a provider of innovative optical components based on its patented “direct optical wiring” (DOW) technology, will demonstrate the advantages of using DOW for immersion cooling in the data center today through April 3rd at OFC 2025 in booth 5221 at the Moscone Center. Hyperscalers and other data center operators are turning towards immersion cooling as it offers significantly higher thermal efficiency and allows for greater rack density and energy savings compared to traditional air cooling.

Immersion cooling can reduce energy consumption by up to 50% compared to air cooling, is quieter than air cooling and allows for higher rack densities (up to 10X), which enables more computing power in less space.

DOW is polymer-based air-cladded waveguide technology that replaces the use of lens optics in transceivers. It is a direct coupling method (see associated image) that creates a hermetically-sealed environment and, as a result, protects the optics in the transceivers from the cooling fluids. Therefore, a transceiver manufacturer using DOW would avoid the costs incurred for the additional sealing, packaging or assembly required to make their products suitable for immersion cooling.

Other features of DOW (which also offers benefits in air-cooling environments) that make it more “immersion cooling friendly” than other manufacturing processes are:

· No use of multi-channel lens assemblies
· No active alignment
· Near-zero optical crosstalk

“Based on the results we have seen in our own testing and with customers in working data center environments, we firmly believe DOW will play an important role in making hyperscale and cloud data center operations more environmentally friendly and better equipped to handle the emerging AI/ML workloads associated with generative AI, agentic AI and other AI techniques,” said Chongcook Kim, CEO of Lessengers.

In addition to the live immersion cooling demonstration, Lessengers will feature at OFC 2025 a live demonstration of its new 1.6T transceiver announced yesterday, 800G/400G optical transceiver and active optical cable products and future connectivity options with co-packaged and near-packaged optics assemblies.