GIGALIGHT introduced its 400G QSFP-DD ER4-30km optical module with a live demonstration at the European Conference on Optical Communication (ECOC) 2025 in Copenhagen. The module uses narrow LAN-WDM wavelengths to deliver a cost-effective long-reach solution for hyperscale data centers and 5G network operators.
The 400G QSFP-DD ER4-30km module supports dual-fiber transmission up to 30km and consumes less than 13W. It features average launch power of up to +3dBm per lane, TDECQ as low as 2.28dB, and receiver OMA sensitivity better than –12.5dBm per lane. Using avalanche photodiode (APD) receiver technology and low-dispersion wavelength emission, the design achieves stable long-distance transmission.
GIGALIGHT validated performance with a 24-hour loopback test over 400GE traffic generators, showing error-free 30km transmission with KP4 FEC and zero packet loss. The module adopts a semi-hermetic laser packaging design, consistent with the company’s 400G FR4 and LR4 offerings, to ensure long-term reliability.
• Dual-fiber transmission up to 30km
• Receiver OMA sensitivity better than –12.5dBm per lane
• Average launch power up to +3dBm per lane
• TDECQ as low as 2.28dB
• Power consumption below 13W
• 24-hour loopback test with zero packet loss
“By combining APD receiver technology with low-dispersion wavelength emission, we have achieved a new level of reliable long-reach optical transmission for 400G networks,” said a GIGALIGHT spokesperson.

🌐 Analysis: The 400G QSFP-DD ER4-30km module addresses demand for extended-reach, high-capacity optical interconnects in AI-driven data center and 5G transport networks. Competitors such as Innolight, Eoptolink, and II-VI (Coherent) have also introduced extended-reach 400G modules, but GIGALIGHT’s focus on balancing long-haul performance with sub-13W power consumption positions it well for cost-sensitive hyperscaler deployments. The semi-hermetic packaging choice reflects industrywide efforts to boost module reliability for multi-year operation.
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