Theoretical and experimental investigation of low-volgage and low-loss 25-Gbps Si photonic crystal slow light Macha??Zehnder modulators with interleaved p junction

摘要

In this study, we investigated the performance of Si lattice-shifted photonic crystal waveguide (LSPCW) Mach-Zehnder modulators theoretically and experimentally. The LSPCW increases the phase shift in modulator to 2.3 - 2.5 times higher, which allows for size reduction and high performance. On-chip passive loss was reduced to less than 5 dB by optimizing each component. We obtained 25 Gbps clear open eye and 3 dB extinction ratio at a drive voltage of 1.5 a?? 1.75 V for 200 ??m phase shifter with linear p junction when we added a modulation loss of 7 dB. This modulation loss was reduced to 0.8 dB, maintaining other performance, by employing interleaved p junction and optimizing doping concentrations.