100G Single-Lambda? The “Simplified” Revolution of Single-Wavelength Optical Transceivers

Imagine the optical transceivers in your data center as toll booths on an information highway. Traditional methods (such as 100G LR4) require four parallel toll lanes (using four different wavelengths of light) to achieve 100G throughput, with each lane handling 25G of traffic. While this approach is proven, consider this: building four lanes is undoubtedly more expensive than building one, maintaining four sets of equipment consumes more power, takes up more space, and ensuring they don’t interfere with each other is quite a hassle.

Now, a new technology called “single-wavelength” (such as 100G DR1/FR1/LR1) has emerged! Its core concept is simple yet powerful: using just one lane (one wavelength) to directly handle 100G traffic! It’s like upgrading a toll booth to a super-efficient single-lane system, where one vehicle can handle the capacity of four.

How does it achieve this? The key lies in two key points:

Modulation technology upgrade: Previously, “one car per lane” (NRZ modulation) was used, but now the more intelligent “two cars per lane” technology (PAM4 modulation) is used. Information density has doubled!

Increased integration: Thanks to advanced processes such as silicon photonics, the “toll booth equipment” within the optical module (lasers, modulators, detectors, etc.) has been made smaller and more compact, integrated on a single chip.

This “minimalism” brings tangible benefits:

Money savings! Lower costs:

• Fewer parts: Previously, four sets of core components such as lasers and detectors were required; now only one set is needed. Fewer parts saves money on parts purchases.
• Easy assembly: Eliminating the laborious task of precisely coupling four wavelengths of light (one of the most time-consuming and labor-intensive steps in traditional LR4 modules) improves production efficiency and yield..

Energy Saving! Lower Power Consumption:

Reducing the number of core components from four to one naturally reduces power consumption. Think about it: which consumes more power: driving four lasers or one laser? A Cisco blog post mentions that single-wavelength modules can significantly reduce power consumption compared to traditional four-wavelength modules. This is crucial for data centers striving for green energy conservation and lower operating costs.

More Reliable! Fewer Failure Points:

With fewer parts, there are fewer things to fail. Simplified assembly reduces the risk of human error or misalignment. The overall module stability is also improved.

Future-proof! Smoother Upgrades:

Currently, the mainstream single-wavelength module is 100G (such as LR1). Future 400G, 800G, and even 1.6T high-speed modules will primarily utilize multiple parallel single-wavelength channels (for example, 400G-DR4 utilizes four parallel 100G channels). By deploying single-wavelength 100G modules now, much of the infrastructure (especially fiber cabling) can be directly reused when upgrading to higher speeds in the future, significantly reducing upgrade costs and complexity. This is what we call “future-proofing.”

In summary, the core advantage of single-wavelength optical modules (such as 100G LR1/DR1/FR1) lies in their simplicity:

• Simplified principle: One wavelength performs the work of four wavelengths (via PAM4 modulation).
• Simplified structure: Fewer components and higher integration.
• The result: savings in cost and power, greater reliability, and easier upgrades.

For enterprises building or upgrading data centers and 5G networks, especially those pursuing cost-effectiveness, energy conservation, and future-oriented scenarios, single-wavelength optical modules are demonstrating strong appeal and competitiveness, offering a strong challenger and alternative to traditional four-wavelength modules (such as 100G LR4). This “minimalist revolution” in optical communications is making high-speed network connections simpler, more economical, and more efficient.