Immersion DAC / AOC Solutions for AI and High-Density Data Centers

As AI clusters, high-performance computing systems, and hyperscale data centers continue increasing compute density, traditional air cooling is facing greater thermal challenges.

High-power GPUs, accelerators, network adapters, and high-speed switches can generate substantial heat inside densely populated racks. As a result, more data center operators are evaluating immersion liquid cooling to improve thermal efficiency and support higher rack densities.

However, moving network equipment into dielectric cooling liquid affects more than servers and switches.

The high-speed interconnect cables connected to these systems must also be designed with the immersion environment in mind.

For Taiwan manufacturer Optech, this creates an important new area of high-speed connectivity:

Immersion DAC and Immersion AOC solutions.

Optech can support immersion cooling projects with high-speed Direct Attach Copper (DAC) and Active Optical Cable (AOC) products, as well as customized mechanical, cable, material, firmware, labeling, and connector requirements.

Depending on the target platform and project configuration, Optech can work with customers on high-speed connections for:

• AI training clusters
• GPU servers
• HPC systems
• high-density switching
• cloud data centers
• immersion-cooled racks
• liquid-cooled network infrastructure

For eligible procurement projects, Taiwan-origin and TAA options are also available.

What Is an Immersion DAC Cable?

A DAC, or Direct Attach Copper cable, is a high-speed copper cable assembly with integrated connectors on both ends.

DAC is commonly used for short-distance connections between:

• switches
• servers
• network adapters
• storage systems
• AI accelerators

An Immersion DAC is a DAC solution designed or customized for use in equipment exposed to dielectric cooling fluid.

Compared with a standard air-cooled DAC, an immersion-oriented design may require additional consideration of:

• cable jacket material
• connector housing
• pull-tab materials
• plastics and elastomers
• adhesives
• cable strain relief
• PCB coatings
• labeling
• long-term fluid exposure
• corrosion resistance
• mechanical durability

The objective is to maintain stable electrical and mechanical performance while operating in an immersion environment.

What Is an Immersion AOC Cable?

An AOC, or Active Optical Cable, combines optical transceiver electronics with fiber inside a permanently attached cable assembly.

Instead of transmitting high-speed signals through copper conductors across the entire cable, AOC converts electrical signals into optical signals inside the connector assembly.

This makes AOC especially useful when the required transmission distance exceeds the practical reach of passive copper DAC.

An Immersion AOC must consider both electronic and optical components operating close to or inside the immersion environment.

Important engineering considerations can include:

• optical engine protection
• cooling-fluid compatibility
• cable jacket compatibility
• connector material stability
• optical fiber routing
• sealing and mechanical construction
• thermal behavior
• EEPROM and firmware compatibility
• long-term reliability

For high-density AI systems, AOC can provide an attractive balance between high bandwidth, longer reach, lower cable weight, and easier routing.

Immersion DAC vs Immersion AOC

DAC and AOC address different physical network requirements.

Feature	Immersion DAC	Immersion AOC
Transmission medium	Copper	Optical fiber
Typical application	Short reach	Short to medium reach
Power consumption	Generally lower	Higher than passive DAC
Cable weight	Heavier at higher speeds	Lighter
Cable flexibility	Depends on AWG and speed	Generally easier to route
Cost	Usually lower	Usually higher
Electronics	Minimal in passive DAC	Active optical electronics
Best fit	Same rack / adjacent equipment	Longer in-rack or rack-to-rack links
Immersion considerations	Copper cable and connector materials	Optical engine, fiber, connector and materials

Neither solution is universally better.

The correct choice depends on:

• required distance
• cable routing
• switch architecture
• GPU server layout
• power target
• rack density
• available space
• immersion-fluid specification

Why Immersion DAC and AOC Matter for AI Infrastructure

AI networks are moving toward increasingly dense interconnect architectures.

A single AI rack may contain multiple GPU servers, NICs, DPUs, switches, and hundreds of high-speed interfaces.

At this density, cable selection directly influences:

• airflow or liquid-flow paths
• installation complexity
• rack serviceability
• signal integrity
• power consumption
• network reliability

Immersion cooling changes the design environment further because cable assemblies may be exposed to liquid for extended periods.

This creates a need for high-speed cables specifically evaluated or customized for the intended environment.

Key Advantages of Immersion DAC Solutions

1. Low-Latency Short-Reach Connectivity

DAC provides a direct electrical connection between two ports.

Because passive DAC does not require optical conversion, it can be an attractive choice for low-latency short-distance applications.

This is especially useful for:

• GPU server to switch
• NIC to switch
• DPU to switch
• switch to switch
• same-rack AI networking

2. Lower Power Consumption

Passive DAC generally consumes less power than optical alternatives because it does not require optical transmitters and receivers.

In high-density AI infrastructure containing hundreds or thousands of links, reducing interconnect power can be valuable.

3. Cost Efficiency

For short-reach applications, DAC is often more economical than deploying separate optical transceivers and fiber cables.

4. Simple Installation

DAC is an integrated cable assembly.

There is no need to purchase and install two separate optical modules plus a fiber patch cable.

5. Suitable for Dense AI Racks

When designed correctly, DAC can provide reliable short-distance connectivity inside dense liquid-cooled AI racks.

Key Advantages of Immersion AOC Solutions

1. Longer Reach Than Passive DAC

As data rates increase, practical copper reach generally becomes shorter.

AOC uses optical transmission and can therefore support longer connections while maintaining high bandwidth.

2. Lighter Cable Construction

High-speed copper cables can become thick and heavy.

AOC uses optical fiber, making the cable easier to route in high-density environments.

3. Smaller Bend and Routing Burden

Depending on the cable design, AOC can provide easier routing through complex AI rack architectures.

4. Reduced Electromagnetic Interference

Because the high-speed signal travels optically through the cable, AOC is less susceptible to electromagnetic interference along the fiber section.

5. Strong Fit for Rack-to-Rack Connectivity

AOC is particularly useful when equipment is too far apart for practical passive DAC deployment but does not require a fully modular transceiver-and-fiber solution.

Optech Immersion DAC / AOC Product Capabilities

Optech provides high-speed cable solutions across multiple data rates and form factors.

Depending on the project, Optech can evaluate immersion-oriented DAC and AOC configurations for interfaces such as:

• SFP28
• QSFP28
• QSFP56
• QSFP-DD
• QSFP112
• OSFP
• OSFP112
• next-generation high-speed interfaces

Applications may include 25G, 100G, 200G, 400G, 800G, and other project-specific high-speed connections.

Exact immersion compatibility should be evaluated according to the cooling fluid, host platform, cable configuration, and operating conditions.

Immersion DAC Breakout and Fanout Solutions

AI and data center networks frequently require breakout connections.

For example, one high-speed switch port may need to connect to multiple server or NIC ports.

Optech can evaluate customized breakout architectures such as:

• high-speed port to multiple lower-speed ports
• OSFP to QSFP-based breakout
• QSFP-DD breakout
• QSFP112 breakout
• custom lane mapping
• asymmetric connector configurations

This capability can be particularly useful in immersion environments where cable routing is constrained by tank design and equipment placement.

Instead of forcing the data center to adapt to a standard cable, Optech can work with customers to develop the cable around the actual deployment.

Optech Customization Capability for Immersion DAC / AOC

Immersion cooling projects often require more customization than conventional air-cooled data centers.

The dielectric fluid, tank design, server orientation, cable routing, and switch location can vary significantly between projects.

Optech can work with customers on project-specific requirements including:

Cable Jacket Material

The external jacket may need to be selected according to the cooling fluid used by the customer.

Material evaluation may consider:

• swelling
• softening
• cracking
• fluid absorption
• chemical resistance
• long-term durability

Connector and Pull-Tab Design

Traditional pull tabs and connector components may behave differently when continuously exposed to liquid.

Customized materials or mechanical designs can be evaluated.

Cable Length

Standard cable lengths may not work efficiently inside an immersion tank.

Optech can support project-specific cable lengths to improve routing and reduce unnecessary cable loops.

Breakout Configuration

Custom breakout and fanout configurations can be developed according to switch, NIC, or GPU server architecture.

EEPROM and Firmware Coding

Active cable assemblies may require host-specific EEPROM or firmware configuration.

Optech can support compatibility-oriented coding based on the target platform.

Labeling and Serial Numbers

Customers can request customized:

• labels
• part numbers
• serial-number formats
• customer logos
• barcodes
• QR codes
• country-of-origin markings

For immersion environments, label material and adhesion can also be evaluated.

Material Compatibility Is Critical

One of the most important factors in an immersion cable project is cooling-fluid compatibility.

Not every dielectric fluid has the same chemical composition.

Different fluids can interact differently with:

• PVC
• TPE
• TPU
• silicone
• rubber
• adhesives
• plastics
• coatings
• printed labels

A cable that is compatible with one fluid should not automatically be assumed compatible with another.

For this reason, customers should provide the exact coolant manufacturer and fluid model during project evaluation.

Optech can then review the cable construction and determine what customization or validation may be required.

Application Scenario 1: GPU Server-to-Switch Connections

One of the most common AI networking links is between a GPU server's high-speed NIC and a Top-of-Rack or Leaf switch.

When the server and switch are located close together inside or near the same immersion system, Immersion DAC can provide:

• low latency
• low power
• simple installation
• cost-efficient short-reach connectivity

This makes DAC particularly attractive for dense scale-out AI fabrics.

Application Scenario 2: High-Density AI Training Clusters

Large AI clusters can contain thousands of GPU network interfaces.

At this scale, the interconnect solution must be:

• reliable
• easy to install
• easy to replace
• predictable in performance
• compatible with the target switch and NIC

Immersion DAC and AOC can support short- and medium-reach connectivity depending on the physical layout.

Application Scenario 3: Rack-to-Rack AI Connectivity

When racks are positioned farther apart, passive DAC may no longer provide sufficient reach.

In these cases, Immersion AOC can provide longer optical transmission while retaining a plug-and-play cable architecture.

This can simplify deployment compared with purchasing separate optical modules and fiber patch cables.

Application Scenario 4: HPC and Supercomputing

HPC environments require high-bandwidth, low-latency communication between compute nodes and network switches.

Immersion cooling is increasingly relevant as compute power density rises.

Customized DAC and AOC solutions can provide high-speed connections while supporting the physical and thermal requirements of the HPC system.

Application Scenario 5: Cloud GPU Infrastructure

GPU cloud providers frequently expand hardware capacity and change network configurations.

Pre-terminated DAC and AOC assemblies can simplify deployment and replacement, while customized cable lengths can improve cable management inside dense immersion systems.

Application Scenario 6: Immersion-Cooled Network Switches

Some immersion designs submerge not only servers but also networking equipment.

This creates additional requirements because every high-speed cable attached to the switch may be continuously exposed to dielectric fluid.

Optech can evaluate:

• connector construction
• cable jacket
• pull-tab materials
• strain relief
• firmware coding
• cable length
• breakout structure

according to the specific immersion network design.

Application Scenario 7: Custom AI Network Architectures

Not every AI cluster follows a standard rack architecture.

Some systems require:

• unusual switch placement
• custom cable exit points
• multiple breakout configurations
• specialized tank layouts
• mixed-speed connections

This is where Optech's customization capability becomes particularly valuable.

400G and 800G Immersion Cable Applications

Higher-speed network generations create additional challenges for copper links.

As lane speeds increase, insertion loss and signal integrity become increasingly important.

This makes careful cable design essential.

For 400G and 800G environments, customers may choose among:

Passive DAC for the shortest links

Active Copper Cable / AEC-type solutions where electrical reach needs to be extended

AOC for longer, lighter optical links

Pluggable optical transceivers for longer-reach and structured fiber applications

Optech can help customers select the appropriate interconnect based on:

• distance
• power
• topology
• cable density
• platform
• cooling environment

Immersion DAC / AOC for Ethernet and InfiniBand

AI infrastructure may use either Ethernet or InfiniBand.

Although the physical connector may look identical, the host system can require different:

• firmware
• EEPROM coding
• lane configuration
• FEC behavior
• port breakout settings

Therefore, Optech recommends confirming the exact target platform before production.

Typical project information may include:

• switch manufacturer
• switch model
• NIC or DPU model
• firmware version
• Ethernet or InfiniBand
• desired port speed
• breakout configuration

This allows the cable to be configured for the actual network rather than treated as a generic assembly.

Passive DAC, Active Copper, or AOC?

Choosing the right high-speed cable requires evaluating the physical network.

A practical approach is:

Very short distance → Passive DAC

Best when low power and low cost are the highest priorities.

Longer copper reach → Active Copper / AEC

Useful when additional reach is required while maintaining copper-based connectivity.

Longer or lighter connection → AOC

Useful when fiber-based transmission provides better routing and reach.

Structured or long-distance network → Optical Transceivers + Fiber

Best when modularity, longer reach, or structured cabling is required.

For immersion projects, Optech can evaluate all of these architectures according to the actual equipment and cooling design.

Why Custom Cable Length Matters in Immersion Tanks

In a normal data center, excess cable can often be routed through cable managers.

Inside an immersion tank, excessive cable length can create additional problems.

It may:

• obstruct liquid flow
• make equipment removal more difficult
• increase cable congestion
• create unnecessary bending
• complicate service procedures

Custom cable lengths can therefore provide more value in immersion applications than in conventional racks.

Optech can produce cable assemblies according to the physical dimensions of the customer's immersion system.

Benefits of Optech Immersion DAC / AOC Solutions

Optech combines high-speed connectivity with project-specific engineering support.

Key advantages include:

High-Speed Interconnect Capability
Solutions for multiple generations of data center and AI networking.

Immersion-Oriented Customization
Materials, cable lengths, connector components, labels, and mechanics can be evaluated according to the project.

DAC and AOC Options
Customers can select the appropriate architecture according to distance and power requirements.

Breakout Capability
Custom fanout solutions can support high-density switch architectures.

Platform Compatibility Support
EEPROM and firmware can be configured for target systems where applicable.

Taiwan Manufacturing
Optech provides Taiwan-based production, engineering, and project coordination.

TAA Options
Taiwan-origin and TAA options are available for eligible projects.

OEM / ODM Support
Custom part numbers, branding, labeling, and cable architecture can be supported.

What Information Should You Provide to Optech?

For an Immersion DAC / AOC project, providing complete technical information helps speed up evaluation.

Customers should ideally provide:

• required data rate
• DAC or AOC preference
• connector on Side A
• connector on Side B
• target switch
• target NIC / DPU / server
• Ethernet or InfiniBand
• required cable length
• breakout requirement
• cooling-fluid manufacturer
• cooling-fluid model
• single-phase or two-phase immersion
• operating temperature
• expected immersion duration
• sample quantity
• volume forecast
• TAA requirement

If these details are not fully known, Optech can also work with customers during the early design stage to determine the appropriate configuration.

From Custom Sample to Volume Production

An immersion cable project can follow a structured development process:

Requirement Review → Material Selection → Cable Design → Sample Production → Immersion Evaluation → Platform Compatibility Testing → Customer Qualification → Volume Production

This approach helps reduce the risk of moving directly from a standard air-cooled cable to large-scale immersion deployment without sufficient validation.

Optech welcomes engineering discussions and joint qualification projects.

Taiwan Manufacturing and TAA Options

For government, public-sector, research, education, defense-related, and regulated procurement projects, supply-chain origin can be an important requirement.

Optech is a Taiwan-based high-speed connectivity manufacturer.

For eligible configurations, Optech can support Taiwan-origin / TAA-oriented DAC and AOC products.

Depending on the project, supporting documentation may include:

• country of origin
• manufacturing information
• serial-number list
• customized labeling
• product traceability
• compliance documentation

Final TAA status should be confirmed for the specific product configuration and applicable procurement rules.

Why Choose Optech for Immersion DAC / AOC?

Immersion cooling requires more than a standard catalog cable.

The cable becomes part of the thermal and mechanical architecture of the system.

Optech can work with customers across multiple aspects of the project:

• DAC
• AOC
• breakout cables
• active copper interconnects
• custom cable lengths
• immersion-compatible material evaluation
• platform-specific coding
• mechanical customization
• customized labeling
• serial-number management
• OEM / ODM projects
• sample qualification
• volume manufacturing
• Taiwan-origin solutions
• TAA options

This gives customers a single partner for both high-speed interconnect engineering and project customization.

Ready for Your Immersion Cooling Project?

As AI networks move toward higher GPU density, higher power consumption, and 400G/800G-class connectivity, cooling and network cabling must increasingly be designed together.

Immersion DAC and AOC solutions can provide efficient, high-speed connectivity inside next-generation liquid-cooled data centers.

Whether your application requires short-reach low-power DAC, lightweight optical AOC, breakout connectivity, or a fully customized immersion cable architecture, Optech can work with your engineering team from prototype through production.

Contact Optech for samples, customized design, platform compatibility evaluation, TAA options, project pricing, and volume orders.

Suggested SEO Structure

H1: Immersion DAC / AOC Solutions for AI and High-Density Data Centers

H2: What Is an Immersion DAC Cable?
H2: What Is an Immersion AOC Cable?
H2: Immersion DAC vs Immersion AOC
H2: Why Immersion DAC and AOC Matter for AI Infrastructure
H2: Key Advantages of Immersion DAC Solutions
H2: Key Advantages of Immersion AOC Solutions
H2: Optech Immersion DAC / AOC Product Capabilities
H2: Immersion DAC Breakout and Fanout Solutions
H2: Optech Customization Capability for Immersion DAC / AOC
H2: Material Compatibility Is Critical
H2: Typical Application Scenarios
H2: 400G and 800G Immersion Cable Applications
H2: Immersion DAC / AOC for Ethernet and InfiniBand
H2: Passive DAC, Active Copper, or AOC?
H2: Why Custom Cable Length Matters in Immersion Tanks
H2: Benefits of Optech Immersion DAC / AOC Solutions
H2: What Information Should You Provide to Optech?
H2: From Custom Sample to Volume Production
H2: Taiwan Manufacturing and TAA Options
H2: Why Choose Optech for Immersion DAC / AOC?
H2: FAQ

FAQ

1. What is an Immersion DAC?

An Immersion DAC is a direct attach copper cable designed or customized for use in equipment exposed to dielectric cooling fluid. Material compatibility, cable jacket, connector construction, labels, and long-term fluid exposure should all be considered.

2. What is an Immersion AOC?

An Immersion AOC is an active optical cable designed or adapted for immersion cooling environments. It integrates optical electronics and fiber into a complete cable assembly while taking cooling-fluid compatibility into consideration.

3. What is the difference between Immersion DAC and Immersion AOC?

DAC transmits signals electrically over copper and is typically best suited to shorter connections. AOC converts the signal to optical transmission and is generally better for longer, lighter, and more flexible connections.

4. Does Optech provide Immersion DAC and AOC products?

Yes. Optech can support immersion-oriented high-speed cable projects and work with customers on product selection, material evaluation, customization, platform compatibility, samples, and production.

5. Can Optech customize cable length?

Yes. Project-specific cable length is an important part of immersion design because unnecessary cable loops can increase congestion and interfere with serviceability or liquid flow.

6. Can Optech produce breakout Immersion DAC or AOC?

Depending on the interface and project requirements, Optech can evaluate custom breakout and fanout configurations for high-density network applications.

7. What cooling fluids are supported?

Compatibility depends on the specific dielectric fluid and cable materials. Customers should provide the coolant manufacturer and exact product model so Optech can evaluate the project requirements.

8. Can standard DAC or AOC cables simply be submerged?

It is not recommended to assume that a standard air-cooled cable is suitable for long-term immersion. Cable jackets, adhesives, plastics, labels, and active components may behave differently in different dielectric fluids.

9. Is DAC better than AOC for AI clusters?

It depends on distance and architecture. DAC is usually attractive for very short links because of its low power and cost, while AOC is useful when longer reach, lower cable weight, or easier routing is required.

10. Can Optech support 400G and 800G immersion cable projects?

Optech can evaluate high-speed immersion interconnect requirements, including 400G and 800G-class applications, according to the target platform, connector, distance, cable architecture, and cooling environment.

11. Can Immersion DAC/AOC be used with NVIDIA platforms?

Optech can support compatibility-oriented projects for major AI networking platforms. Customers should provide the exact switch, NIC/DPU, firmware version, protocol, cable length, and port configuration for evaluation.

12. Can the cables support both Ethernet and InfiniBand?

The physical cable architecture may be applicable to both environments, but host coding, lane configuration, FEC, and platform requirements may differ. The exact application should therefore be confirmed before production.

13. Does Optech offer TAA-compliant Immersion DAC / AOC?

Optech can provide Taiwan-origin and TAA options for eligible product configurations. Final TAA compliance should be confirmed according to the specific manufacturing process and procurement requirements.

14. Can customers request samples before placing a production order?

Yes. Optech can support engineering samples for customer immersion and platform qualification before volume production.

15. Does Optech provide OEM / ODM customization?

Yes. Optech can support project-specific cable lengths, connector configurations, coding, labels, serial numbers, branding, mechanical design, and other OEM/ODM requirements.

Conclusion

As AI infrastructure moves toward higher compute density and more advanced liquid-cooling architectures, high-speed interconnect cables must evolve alongside servers and switches.

Immersion DAC provides a practical solution for short-reach, low-power, low-latency connectivity, while Immersion AOC provides greater reach, lighter cabling, and easier routing for larger AI environments.

By offering DAC, AOC, breakout solutions, customization capability, platform compatibility support, Taiwan manufacturing, OEM/ODM services, and TAA options, Optech can help customers develop high-speed connectivity specifically for their immersion cooling architecture.

From the first engineering sample to full production deployment, Optech welcomes Immersion DAC / AOC projects and volume orders worldwide.

Contact Optech today for samples, customized solutions, project pricing, compatibility support, and TAA requirements.