A 90.7%-Efficiency Hybrid Optogenetic Stimulation System with Sub-Threshold Electrical Stimuli Achieving 70.6% Optical Energy Saving. - Joonghoon Kang; Hyeonhee Roh; Kyeongho Eom; Hyun-Su Lee; Hojae Chon; Maesoon Im; Hyung-Min Lee (ISSCC, 2026)