What fiber and connector does 400G QSFP-DD FR4 need?
Duplex single-mode fiber on Duplex LC, listed for 2km. It reuses ordinary structured single-mode cabling, which is usually why it is chosen over a parallel option at the same rate.
400G Optical Transceivers Product Detail
400G QSFP-DD FR4
400G QSFP-DD FR4 is a QSFP-DD FR4 option using Duplex LC for 2km single-mode fiber links.
Product specification information
Use the published model direction and key parameters for selection and sample planning. Confirm compatibility coding, optional temperature grade, and production parameters in the formal specification or order document.
- Product family
- QSFP-DD FR4
- Optical interface
- Duplex LC
- Typical reach
- 2km
- Transmission medium
- Single-mode Fiber
QSFP-DDFR4Duplex LC2km SMFQSFP-DD FR4
Compare 400G DR4, FR4 and LR4 → Review reach, fiber, connector, breakout and link-budget boundaries before selecting the final model. 
Specs & Features
Features and specifications
For the latest specification and samples, contact sales@staricatech.com.
Product overview
400G QSFP-DD FR4 is designed for 2km links using Duplex LC. Selection must confirm the host form factor, electrical interface, PMD, FEC, fiber mapping, power and thermal limits, software version and the remote endpoint; the model name alone does not establish interoperability.
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QSFP-DD FR4 form factor for the defined host-port direction.
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Duplex LC interface for 2km links.
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WDM single-mode optical transmission; confirm the exact fiber or cable assembly before ordering.
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Validate host coding, FEC, diagnostics, power, thermal behavior and long-duration stability.
Selection and deployment notes
- Before ordering 400G QSFP-DD FR4, confirm the exact host, software, port mode, reach, fiber or cable, connector, FEC, temperature, quantity, compatibility coding and delivery version.
Form factor
QSFP-DD
Data rate
400G
Fiber type
Single-mode Fiber
Compatibility validation
Confirm against the target host, software, port mode and FEC
Product
400G QSFP-DD FR4
Transmission
WDM single-mode optical transmission
Interface
Duplex LC
Typical reach
2km
Applications
AI clusters and high-density data-center interconnects
Delivery support
Samples, compatibility review and lead-time assessment
- AI clusters and high-density data-center interconnects
- Compatibility and sample validation
- Network rollout and replacement planning
- Lab and acceptance testing
Selection FAQ
400G QSFP-DD FR4 selection questions
How does 400G QSFP-DD FR4 differ from a parallel single-mode module at the same rate?
400G QSFP-DD FR4 carries the full rate over a single fiber pair, so it drops into existing duplex cabling. A parallel variant needs an MPO trunk and is chosen when the plan is to break the link out to lower-rate ports. Reach targets also differ, so compare against the measured link budget.
What do I need to specify to request a quote for 400G QSFP-DD FR4?
Give the host vendor, model and software version at both ends, the QSFP-DD port or lane mode, the operating temperature range, the quantity per site and the target delivery date. For 400G QSFP-DD FR4 also state the measured link distance and the number of patch points in the path. Compatibility is confirmed per platform, so the host details matter as much as the optical specification.
Related Products
Related 400G Optical Transceivers products
400G QSFP-DD DR4
400G QSFP-DD DR4 is a QSFP-DD DR4 option using MPO-12 for 500m single-mode fiber links.
400G QSFP-DD LR4
400G QSFP-DD LR4 is a QSFP-DD LR4 option using Duplex LC for 10km single-mode fiber links.
400G QSFP-DD SR8
400G QSFP-DD SR8 is a QSFP-DD SR8 option using MPO-16 for 100m OM4 multimode fiber links.