表題番号：2025C-529
日付：2026/03/31
研究課題フォトニック結晶導波路を用いたマッハツェンダ変調器の研究
| 研究者所属（当時） | 資格 | 氏名 | |
|---|---|---|---|
| （代表者） | 理工学術院 大学院情報生産システム研究科 | 准教授 | 高畑 清人 |
- 研究成果概要
- In our previous work, application of the silicon (Si) slow-light photonic crystal waveguide (PCW) in the perturbed kagome lattice to a compact carrier-injection type electro-optic (EO) phase shifter in a 2 × 2 Si Mach–Zehnder interferometer optical switch was numerically demonstrated. In this study, the slow-light PCW has been used for a compact carrier-depletion type EO phase shifter in a Si Mach–Zehnder modulator (MZM). A compact Si passive phase bias is introduced in the phase-shifting arm of the MZM to adjust the initial phase offset between the two arms. At an operating wavelength of 1545 nm, the insertion loss of the phase shifter is estimated to be approximately 6 dB, including the coupling loss between the PCW and the strip waveguide, as well as the propagation loss in the PCW. Assisted by the slow-light PCW in the perturbed kagome lattice with a high group index of 71, the phase shifter was designed in a compact size of 22 um and required a significantly small half-wave voltage-length product of only 4.76×10-2 V∙cm. The RC-limited 3-dB bandwidth of the designed MZM is calculated to be 7.30 GHz. It also exhibits static ER and modulation loss of 3.16 dB and 1.65 dB, respectively, under a driving voltage of 5 Vpp. Furthermore, in numerical simulation, the MZM exhibited a clear eye diagram for 15-Gbit/s NRZ modulation.These results were presented at GlobalNet Workshop (GNW) 2026 held in Fukuoka in March 2026, where the presenter won the outstanding presentation award. We are currently working on a redesigned version aimed at improving performance, and we plan to submit the results to an academic journal.