Knowledge of fiber optics test and measurement equipment including BERTs, sampling/real-time oscilloscopes, VNAs, spectrum analyzers, optical spectrum analyzers, optical power meters, wavelength meters, tunable lasers, attenuators, thermal control systems, and automated handlers. Expertise selecting PCB materials and stackups for high-frequency applications, including Rogers, Panasonic and equivalent low-loss laminate families, hybrid stackups, prepreg/core choices, resin systems, glass weave effects, fabrication tolerances, and cost/performance tradeoffs.