What Is Single-Lambda and Where Does It Work?

At GNM, we use a variety of optical modules - from traditional designs to next-generation solutions. Single-Lambda modules have become a key part of our technical toolkit, alongside other formats that allow us to flexibly adapt to the architecture of specific networks.

What is Single-Lambda and Where It Works

Single-Lambda is a modular standard based on PAM4 modulation, enabling transmission of 100G or 400G over a single wavelength (λ). This differs from classical approaches, where 100G is transmitted as 4×25G NRZ across multiple wavelengths. The architecture was standardized under the 100G Lambda MSA and is widely used in today’s high-density infrastructures.

Benefits of Single-Lambda in Real-World Deployments

🔸Energy efficiency

Up to 30–50% lower power consumption per port compared to QSFP28 LR4. This is crucial when scaling and operating in high-traffic-density environments.

🔸Environmental sustainability

Less hardware = less energy consumption = reduced carbon footprint (Scope 2 and 3). This aligns with our clients’ ESG strategies.

🔸Cost optimization (TCO)

By reducing the number of optical components per channel (only one transmitter and receiver instead of four) and simplifying connection schemes. This lowers module costs and eases configuration and support - especially when scaling to 400G and beyond.

But It’s Not a One-Size-Fits-All Solution

We don’t standardize around a single technology. Depending on the task, other formats may be used:

🔸WDM schemes with multi-wavelength solutions - when traffic aggregation or operation in complex linear environments is required

🔸100G SR4 / ER4 and other specialized modules - for non-standard scenarios

Key Factors We Consider When Selecting Optics:

🔸Calculated link budget (distance + losses)

🔸Topology: presence of splices, splitters, MUX/DEMUX

🔸Power profile and resiliency requirements

🔸Hardware compatibility and solution maturity

🔸Environmental impact (including Scope 3)

🔸Scalability potential and total cost of ownership

Single-Lambda is more than just another format - it’s a practical tool that delivers scale, efficiency, and sustainability in real networks. At GNM, we choose what’s proven - tested in the field and shaped by real-world demands.

At GNM, our approach is grounded in practice. We adopt technologies based on performance in the field - always aligned with real customer needs.

Explore real-world optical solutions with GNM. Visit gnm.net to learn more.