Coherent Optical Transceiver 400G ZR/ZR+ OSNR – Official Technical Overview & Hardware Datasheet

EXECUTIVE SUMMARY

The Coherent Optical Transceiver 400G ZR/ZR+ OSNR represents a paradigm shift in metro, regional, and data center interconnect (DCI) architectures, enabling the direct injection of 400 Gbps coherent wavelengths into router and switch ports without the need for external transponder shelves. By integrating advanced Digital Signal Processing (DSP), a tunable C-band laser, and a high-performance optical subassembly into a standardized hot-pluggable form factor (QSFP-DD or OSFP), this module delivers unprecedented spectral efficiency and operational simplicity. The critical performance differentiator for ZR+ operation in amplified, multi-span DWDM networks is the Optical Signal-to-Noise Ratio (OSNR) tolerance. Engineered to meet the stringent requirements of OpenZR+ MSA and OIF 400ZR implementation agreements, this transceiver maintains a robust link margin with a required OSNR (back-to-back, EOL) typically specified at 24 dB/0.1 nm for 400G DP-16QAM operation, ensuring reliable transmission over reaches extending to 600 km and beyond in ROADM-based line systems .

ARCHITECTURE & CHASSIS DESIGN

The transceiver is housed in a compact, hot-pluggable QSFP-DD (Type 2A) or OSFP form factor, designed for high-density line card configurations in modern telecom chassis. The internal architecture leverages a state-of-the-art 7 nm or 5 nm coherent DSP ASIC that performs complex modulation (DP-16QAM, DP-8QAM, DP-QPSK) and probabilistic constellation shaping (PCS) in ZR+ modes to maximize reach and capacity. The optical engine integrates a narrow-linewidth, full C-band tunable laser (ITU-T G.694.1 grid, 75/100 GHz spacing with flexible grid support) and a high-responsivity coherent receiver. Thermal management is a critical design pillar; the module features an integrated heatsink and advanced firmware-controlled power dissipation mechanisms to ensure stable operation within the 0°C to 70°C case temperature range, with typical power consumption ranging from Parameter Specification

Form Factor QSFP-DD (Type 2A) / OSFP, Hot-pluggable Data Rate Support 400 Gbps / 300 Gbps / 200 Gbps / 100 Gbps (ZR+ Mode) Modulation Format DP-16QAM (400G), DP-8QAM (300G), DP-QPSK (200G/100G) Transmit Output Power ZR: -10 dBm (Typical) / ZR+: 0 dBm (High Power Option) Receiver Sensitivity (OSNR) 24 dB / 0.1 nm (Back-to-Back, EOL, 400G ZR+) OSNR Tolerance Up to 22.7 dB (Typical ZR+ Link Budget) Wavelength Range Full C-band Tunable (191.3 THz – 196.1 THz) Channel Spacing 75 GHz / 100 GHz (Flexible Grid Support) Chromatic Dispersion Tolerance Up to 20,000 ps/nm (ZR+ Mode) Power Consumption Operating Case Temperature 0°C to 70°C (Commercial) / -5°C to 80°C (Extended) Management Interface CMIS / C-CMIS Compliant, MDIO Compliance OIF 400ZR IA, OpenZR+ MSA, QSFP-DD MSA, RoHS

ORDERING OPTIONS

Available configurations include the standard 400G ZR (OIF compliant, -10 dBm Tx power, up to 120 km) and the enhanced 400G ZR+ (OpenZR+ compliant, high Tx power up to 0 dBm, extended reach up to 600+ km). Both variants are offered in QSFP-DD and OSFP form factors. Customers should specify the desired case temperature range (commercial 0°C to 70°C or extended -5°C to 80°C) and whether C-band tuning or specific grid spacing (75 GHz vs. 100 GHz) is required for their specific line system. For high-density DCI applications requiring maximum spectral efficiency without ROADM traversal, the standard ZR variant is optimal. For metro/regional deployments traversing multiple ROADM nodes and amplified spans, the ZR+ high-power variant with superior OSNR tolerance is recommended .