FADY MASOUD NEXT GENERATION COMPONENTS
SHAPING THE OPTICAL CONNECTIVITY FOR THE AI ERA WITH NEXT-GENERATION COMPONENTS AI is reshaping data centre design as GPU clusters scale to hundreds of thousands of accelerators. Ethernet is moving from 400G, 800G, 1.6T and beyond already on the horizon. Meeting this bandwidth demand requires more than faster optics; it requires the right optical architecture for each link, balancing reach, power, cost, latency, density and operational simplicity.
For more than 15 years, coherent optical technology has been the performance benchmark for high- capacity networking. By using advanced modulation, wavelength selectivity and powerful digital signal processing, coherent systems deliver exceptional spectral efficiency and optical reach. They can carry massive amounts of data across metro, long-haul and submarine networks while compensating for fiber impairments that would overwhelm simpler transmission methods. That performance, however, comes with trade-offs. Traditional coherent optics require sophisticated digital signal processors (DSPs), tunable lasers, high- speed modulators and precision optical components. These elements increase cost and power consumption, making full coherent technology ideal for transport and data centre interconnect
(DCI) applications, but overkill for many shorter links inside and around the data centre. Inside the data centre, intensity- modulated direct detection (IM/DD) has long been the preferred choice for short-reach connectivity. Its simpler architecture provides low-power and attractive cost for server-to-switch, leaf-spine, and campus-style links. Fully retimed IM/DD pluggables use DSPs in both transmit and receive paths to clean up signals and ensure broad interoperability, but that processing adds power, heat and latency as speeds rise.
margin. Full coherent optics can overcome those impairments but comes with cost and power penalties. This is where coherent lite is emerging. It brings the benefits of coherent optics into shorter-reach, high-loss data centre and campus environments, but strips the architecture down to the essentials needed for those applications. Rather than optimizing for thousands of kilometers, coherent lite is tuned for links where IM/DD is not enough and transport-class coherent is too much. COHERENT LITE: RIGHT-SIZING COHERENT FOR AI DATA CENTRES Coherent lite depends on purpose- built photonic integrated circuits (PICs) and optimized DSPs. The PIC must integrate lasers, modulators, detectors and supporting optical functions
AI networking is exposing the limitations of both ends of this
spectrum. IM/DD remains efficient, but optical circuit switching, higher connector counts, patch panels and larger cluster fabrics introduce loss and crosstalk that can exceed its practical
Figure 1: Attributes of coherent lite pluggables
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| ISSUE 44 | Q3 2026
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