Waveguide Engineering in Optical Slot Structure for Efficient Optical Modulation

Abstract

Efficient optical modulation performance in Si slot waveguide is proposed. Low optical group index attributed from the optical confinement in the low-index region benefits strong velocity match between RF and optical mode at higher microwave frequencies. The p–n junction is formed in one of the clad presents near the partially etched slot region. The plasma dispersion effect is being utilized to tune the phase of the optical mode by applying external bias. High modulation speed of 40 Gbps with the high dynamic extinction ratio of 8.7 dB is achieved when a swing voltage of 2.1Vpp is applied across the traveling-wave electrode. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.