Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Paper format. 98-Phys-B2 Electro-Optical Engineering, National Examination December 2017 — a three-hour closed-book examination (one 8.5×11 inch double-sided handwritten note sheet permitted). The cover page states any five of the seven questions constitute a complete paper and only the first five as they appear in the answer book are marked; every question is nonetheless answered in full below so the paper remains a complete study resource. The Question 6 heading carries the stray fragment "rework this one" — almost certainly a candidate's or marker's pencil annotation, reproduced verbatim in the question box below but not a part of the printed exam text.
Reference texts. G. Keiser, Optical Fiber Communications, 4th ed. (fiber modes and dispersion, link power and risetime budgets, LED/laser diode output characteristics, PIN photodiode responsivity and noise, receiver design); B. E. A. Saleh and M. C. Teich, Fundamentals of Photonics, 2nd ed. (semiconductor laser rate equations, photodiode quantum efficiency and noise); A. Yariv, Quantum Electronics / E. Hecht, Optics, 5th ed. (electro-optic modulators and Pockels cells).
