Pilot Photonics' Hybrid Laser Breakthrough
As the demand for AI acceleration, cloud computing, and disaggregated architectures intensifies, traditional copper interconnects are reaching physical limitations. At Pilot Photonics, we're heralding the Everything over Optical™ era by addressing a critical bottleneck in data scaling: the need for high-power, multi-wavelength optical sources.
The Copper Interconnect Bottleneck
Copper interconnects are increasingly inadequate for supporting the exponential growth in bandwidth required by next-generation data centre architectures. At high data rates, the reach of copper interconnects fall dramatically, while the power needed to drive the signals increases substantially
Optical interconnects, in contrast, offer:
- Far more capacity because they can carry many channels simultaneously
- Longer reach due to very low loss even at these high data rates
- Smaller, lighter and more malleable form factor
- Potential for reduced latency due to lower DSP requirements at data rates where copper begins to struggle
The need for change is evident: scalable, efficient, multi-terabit optical interconnects are essential for future connectivity.
Bridging the Gap: From Scale-Out to Scale-Up
We’ve already made the first leap — most modern data centres already rely on optical links such as CWDM4, PSM4, and DR4 to scale-out between racks and clusters, replacing copper in many mid-reach connections. But the next frontier is scale-up: bringing that same optical efficiency inside the system, between accelerators, memory pools, and compute tiles.
Many of the longer links inside the data centre today use four wavelength coarse wavelength division multiplexing (CWDM4). However due to dispersion at high data rates, CWDM with its broad wavelength spacing does not scale well. To continue to meet escalating bandwidth demands, particularly in the scale-up segment, optical links must increase wavelength counts, from today's common 4 wavelength links to 8, 16, or even higher. The industry is now converging on CW-WDM multi-source agreement, allowing denser channel spacing, as shown in the diagram below.
Two primary approaches for the optical source are prevalent in this drive to higher channel count optical links:
- Laser Arrays: Multiple discrete lasers offering high per-channel power but with increased complexity and scalability challenges.
- Comb Lasers: A single source emitting multiple stable wavelengths, offering simplicity and accuracy but lower output power and efficiency because the power is shared among all of the wavelengths.
Laser arrays and comb lasers are each potential solutions to the copper interconnect bottleneck, but each have their own challenges and limitations
A Hybrid Solution: ExCELS™
Pilot Photonics is developing a hybrid solution—ExCELS™ (External Comb-Enhanced Laser Source)—that combines the strengths of both approaches. By integrating a high-accuracy microcomb with a high-power laser array through optical injection locking, ExCELS™ delivers:
- High channel power and wall plug efficiency
- Excellent wavelength stability
- Low relative intensity noise (RIN)
- Compatibility with high data-rate applications (both IM/DD and high order coherent)
Injection Locked Comb Demultiplexing for Enhanced Performance
Our patented chip-scale micro-resonator combs, combined with integrated demultiplexing and amplification, enable a significant increase in comb line power and a substantial improvement in RIN compared to the traditional solution of a SiN comb with passive demultiplexing.
This advancement translates to a capacity boost in high-performance applications such as co-packaged optics (CPO), optical I/O systems as well as traditional pluggable optics. Testing has shown greater than 3X capacity improvement, for the same received optical power.
For CPO, the technology will be implemented in OIF-compliant External Laser Small Formfactor Pluggable (ELSFP), ensuring seamless integration into CPO infrastructure.
Pilot's solution delivers a significant improvement in RIN
CW-WDM Product Portfolio
Pilot Photonics is commercializing CW-WDM MSA focused products:
- LYRA-X: A 16-channel bench-top laser source for testing and validation.
- ExCELS™ Module: An OIF-compliant external laser source combining comb precision with array power, targeting CPO systems.
Both platforms are flexible, customizable, and ready to support AI-scale networking, system prototyping, and future data centre deployments.
Join us as we enable the Everything over Optical™ era.
Contact us at sales@pilotphotonics.com
