DR (Distance Range) optical modules support high-speed data transmission over single-mode fiber up to 500 meters, typically using PAM4 modulation and QSFP/QSFP-DD/OSFP form factors.

Key Specifications

Data Rate and Modulation: DR modules operate at high data rates, such as 100 Gb/s per lane for 100G DR1 or 400 Gb/s for DR4, using PAM4 (4-level Pulse Amplitude Modulation) to double the effective data rate compared to NRZ modulation . Fiber Type and Reach:

• Single-mode fiber (SMF) is used for DR modules.
• Maximum reach: up to 500 meters, suitable for inter-data center or medium-range connections . Form Factors:
• Common form factors include QSFP28, QSFP-DD, and OSFP, enabling high port density and low power consumption in data center environments . Electrical Interface:
• DR modules use host-module electrical interfaces compatible with DSP-based SerDes and RS(544,514) FEC for error correction .
• For 100G DR1 QSFP28, the interface follows IEEE 802.3 CAUI-4 standards . Applications:
• Designed for data center interconnects, medium-range links, and Ethernet-like connections with 1, 2, 4, or 8 lanes.
• Optimized for low latency, low power, and cost efficiency . Additional Notes:
• DR modules are part of a broader classification of optical modules:
  • SR (Short Range): up to 300 m, multimode fiber
  • FR (Long Range): up to 2 km, single-mode fiber
  • LR (Long Range): up to 10 km, single-mode fiber
  • DR modules specifically target medium distances (~500 m) over single-mode fiber . Example: The 100G QSFP28 DR1 module supports 500 m links over single-mode fiber via LC connectors, with compliance to IEEE 802.3bm Annex 83E for transmitter/receiver specifications . DR optical modules are essential for high-speed, medium-distance interconnects, providing a balance between reach, power efficiency, and port density in modern data center networks.