Cryo-Compatible, Silicon Spoked-Ring Modulator in a 45nm CMOS Platform for 4K-to-Room-Temperature Optical Links

Cryogenic operation, at 4.5K, of a vertical-junction silicon microring modulator in a 45 nm CMOS platform is demonstrated. Record resonance-shift efficiency – 46 GHz/V – enables nonthermal tuning in 140 GHz range and up to 10 Gbps OOK modulation with ≤1V
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drive, paving the way to cryogenic optical data egress links.