I. Overview
Chromatic dispersion is widely recognized as a key constraint on the transmission quality of high-speed optical signals. Optical signals at different wavelengths travel at varying speeds in optical fibers, leading to signal broadening and inter-symbol interference. For high-speed links of 100G and above, signal distortion must be corrected via dispersion compensation modules (DCM) or complex DSP algorithms.
As the earliest commercial transmission window in optical fiber communications, the O-band (1260–1360 nm) boasts a core technical edge: it is the inherent zero-dispersion window for standard G.652 single-mode optical fibers. Leveraging this feature, Ruidong Technology has launched a 100G transmission solution integrating O-BAND and DWDM MUX/DEMUX.
II. Core Advantages
Dispersion compensation free with simplified architecture
The link requires no DCM devices, reducing equipment stacking and optical path loss. Its hardware and O&M costs are lower than those of C-band medium/short-haul DWDM systems.
Low distortion and low latency for PAM4 high-speed services
The modules adopt bidirectional PAM4 modulation, with built-in DSP and PFEC error correction algorithms to suppress signal distortion and cut transmission latency. It is ideal for low-latency scenarios such as financial computing and real-time cloud interaction.
Multiple models covering full scenarios from 0 to 40 km
The full product line adopts a passive wavelength division architecture. 10/25/40 km optical modules paired with passive WDM devices support 10–30 km transmission; the 60 km optical module with sufficient optical power margin can reach a maximum of 40 km when paired with passive WDM devices, applicable to data center interconnection, 5G fronthaul and metro bearer networks.
Compared with traditional C-band DWDM (1530–1565 nm): the C-band features the lowest optical fiber attenuation and supports EDFA long-haul amplification, but suffers from high chromatic dispersion. For short/medium-haul links above 100G, dedicated dispersion compensation equipment is mandatory, resulting in higher overall system cost, power consumption and space occupation than the O-Band solution.
In general, the O-Band trades off part of the optical fiber attenuation performance for a zero-dispersion, low-cost architecture, making it the most cost-effective option for 100G transmission in 10–40 km medium/short-haul scenarios.
(Image: 16CH O-BAND DWDM MUX/DEMUX, LC/UPC, 1U Rack)
III. Optical Module Features
| Parameter Item |
Parameter Value |
Parameter Item |
Parameter Value |
| Transmission Rate |
Supports 100 Gbps |
Package Standard |
QSFP28 MSA Specification |
| Wavelength Specification |
O-band DWDM, 200 GHz channel spacing; compatible with 800 GHz LAN-WDM grid |
Hardware Standard |
SFF-8636 Rev 2.10a |
| Transmission Distance |
Built-in PFEC, 10/25/40/60 km over single-mode optical fiber |
Electrical Interface |
4 × 25 G electrical channels |
| Power Supply & Power Consumption |
Single 3.3 V power supply, power consumption < 5.5 W |
Optical Interface |
LC duplex connector |
| Operating Temperature |
Commercial grade case temperature: 0℃ ～ 70℃ |
Safety Certification |
TUV / UL / FDA*1 |
| Management Interface |
I2C interface with integrated DDM digital diagnosis |
Environmental Standard |
RoHS compliant |
QSFP28 100G O-Band DWDM 40KM SM LC Transceiver
IV. Transmission Architecture
To meet diverse transmission distance requirements, Ruidong Technology's standardized O-BAND + passive MUX/DEMUX architecture solutions all support ultra-large capacity 16×100G transmission over single or dual fibers.
4.1 0–30 km Transmission Solution (10 km / 25 km / 40 km Optical Modules)
System Composition
10 km / 25 km / 40 km 100G O-band
DWDM QSFP28 optical modules, passive DWDM multiplexers/demultiplexers, standard single-mode optical fibers, and switches.
- Passive optical path requires no power supply or heat dissipation, with low failure rate and no on-site commissioning needed;
- Built-in DSP + PFEC error correction, paired with natural zero dispersion in the O-band, eliminates the need for DCM;
- Flexible selection among multiple distance models, and the 40 km module can cover 10–30 km with sufficient margin;
- Remote status monitoring of switches is realized via the module's DDM function.
Campus computing interconnection, short-distance dual-active data center DCI within the same city, urban 5G base station fronthaul, and short-haul government & enterprise cloud leased lines.
4.2 30–40 km Transmission Solution (60 km Optical Module)
60 km long-haul 100G O-band DWDM optical modules, passive DWDM multiplexers/demultiplexers, single-mode optical fibers, and switches.
- Larger transmit power and receive sensitivity margin, supporting passive link transmission up to 40 km;
- Adopts a fully passive architecture, with built-in SOA in the optical module, saving cabinet space and hardware costs;
- Also features zero dispersion and no DCM requirement, with unified O&M standards for both long and short-haul links;
- Compatible with existing passive O-BAND WDM equipment; transmission distance can be extended simply by replacing modules, enabling easy upgrade.
Cross-urban data center interconnection, suburban/county long-distance 5G fronthaul, and long-haul metro integrated government & enterprise leased lines.
V. Application Scenarios
The entire solution adopts a passive architecture, covering links within 40 km via optical modules of different specifications. No additional SOA or DCM is required, and it fits three mainstream scenarios:
- Data Center Interconnection (DCI)
- 5G Mobile Communication Fronthaul
- Metro Integrated Bearer Network
- Cost: Zero dispersion eliminates DCM costs, and the fully passive network removes the need for SOA, reducing upfront hardware investment; low module power consumption cuts long-term electricity expenses.
- Fiber Resource Utilization: 16-channel wavelength division multiplies single-fiber capacity by 16 times, easing the strain on pipeline fiber resources.
- Scenario Adaptability: Four distance grades of optical modules work with the same set of passive devices, fully covering medium/short-haul services within 40 km.
- O&M Reliability: Passive components have no power-related failure points, enabling unified O&M across the entire link; built-in PFEC ensures low bit error rate over long distances, satisfying 7×24 hour telecom-grade operation requirements.
Against the backdrop of the widespread adoption of computing networks, 5G and cloud-network integration, Ruidong Technology's passive O-band DWDM end-to-end transmission solution, with its core strengths of low cost, easy deployment, high reliability and full 0–40 km distance coverage, has become a preferred solution for 100G high-speed wavelength division bearer in medium and short-haul scenarios.
