Models, circuits, correction, timing, and verification for short-haul optical and copper links.
High-speed links are chains of dependent physical and electronic decisions. A laser or microring driver shapes the optical plant; packages and channels add loss, reflection, memory, and jitter; receiver bandwidth, noise, equalization, and sampling determine what can be recovered. The program treats these as one link rather than a collection of isolated blocks.
The historical radio-over-fibre work established a pattern that remains useful for short-reach photonics: derive a credible nonlinear plant model, identify the distortion visible at the receiver, and place a stable inverse or adaptive correction where it can be implemented efficiently. Current questions extend this method to laser and microring drivers, compact resonator models, DAC and package nonidealities, thermal drift, backscattering, and link-level predistortion.
On the receive side, TIAs, CTLEs, channel correction, sampling, ADCs, serializers/deserializers, and clock-and-data recovery determine whether optical or copper bandwidth becomes useful information. The timing lineage includes oscillators, synthesizers, delay systems, jitter models, and power integrity; the present goal is to join those models to complete receiver and verification flows.
Samy Ghoniemy developed a large-signal semiconductor-laser and link model so that nonlinear intensity and frequency behaviour could be traced into system distortion. The work established the principle that correction must begin with a credible plant model.
Fiona Shearer designed 0.18 μm CMOS cubic-function circuits for cancellation of third-order distortion in radio-over-fibre links. Fabricated measurements exposed both the intended cubic behaviour and practical gain, bandwidth, and test limitations.
Ayman Moktar augmented Fabry–Pérot and distributed-feedback laser equations to model optical back-reflection, identified feedback conditions for isolator-free DFB operation, and combined fibre-Bragg-grating feedback with predistortion to improve analog CATV performance.
Zhan Xu combined second- and third-order correction, multi-tank frequency shaping, and adaptive feedback without requiring a DSP or external numerical optimizer. The 0.18 μm CMOS demonstration reported roughly 5–15 dB distortion reduction over more than 300 MHz around 2 GHz.
Ziad El-Khatib's bidirectional distributed amplifier used cross-coupled linearization. The measured 0.13 μm CMOS design covered approximately 0.1–9.5 GHz, delivered about 5 dB gain in both directions, and reduced third-order intermodulation by as much as 20 dB.
Current work includes short-haul optical and copper channels, process-aware photonic-electronic front ends, compact analog correction, microring-resonator modelling and drive, SerDes/CDR architecture, and auditable AI-assisted verification. Historical circuits, active blocks, and proposed complete-link integrations form a continuous model-correct-observe research program.