We propose a thermo-optic phase shifter utilizing multimode interference in a silicon waveguide. The electrodes were attached to the section where the multimode interference had the minimum optical electric field around the sidewalls. We designed the multimode waveguide width to reduce optical propagation loss in the C–L wavelength band(1.53–1.625 μ m). We succeeded in developing a low optical loss thermo-optic phase shifter with less than 0.1 dB in the wavelength range of 1.5to1.6 μ m. Moreover, wavelength dependence was reduced by adjusting the number of electrodes. An optical switch with the designed thermo-optic phase shifter was fabricated and used to estimate the optical switching time. Switching time of several microseconds was obtained by normal pulse operation, and ultrafast optical switching of about 500 ns was realized by overdrive control.

中文翻译：

---

热光移相器，具有亚微秒级的切换时间和低功耗

我们提出一种在硅波导中利用多模干涉的热光移相器。电极连接到多模干涉在侧壁周围具有最小光电场的部分。我们设计了多模波导宽度，以减少C–L波段（1.53–1.625μm）中的光传播损耗。我们成功开发了一种低光损耗热光移相器，其波长范围为1.5至1.6μm，小于0.1 dB。此外，通过调节电极的数量减少了波长依赖性。制造了具有设计的热光移相器的光开关，并将其用于估计光开关时间。通过正常的脉冲操作可以获得几微秒的切换时间，