中红外波段高速硅基电光调制器设计与优化(特邀)

Design and optimization of high-speed silicon-based electro-optical modulator in mid-infrared band(Invited)

作为中红外波段中最接近O波段和C波段的波段,2μm波段区域逐渐引起人们的广泛关注。主要对2μm波段的马赫-增德尔型调制器进行优化设计和仿真,根据2μm波长下光模场分布的特点,选用具有340 nm厚度顶层硅的SOI衬底,结合实际工艺中240 nm硅刻蚀深度,得到宽度为600 nm以及平板层厚度为100 nm的最优脊波导结构。通过优化掺杂浓度和掺杂区位置获得综合性能最优的调制器器件,在4 V反向偏压下器件光损耗为5.17 dB/cm,调制效率为2.86 V·cm,静态消光比为23.8 dB,3dB EO带宽为27.1 GHz。同时,与220 nm厚度顶层硅器件相比较,器件的综合性能更为优越。研究内容为后续器件实际制作提供了依据,也为后续2μm波段光收发集成模块所需调制器设计提供了新的方向。

The 2 μm wavelength band, which is the closest to the O and C communication band in the midinfrared band, has gradually attracted widespread attention. A Mach-Zehnder modulator in the wavelength of2 μm was optimally designed and simulated. According to the distribution characteristics of the optical mode field in the wavelength of 2 μm, an SOI substrate with the top silicon thickness of 340 nm was selected. Combined with the process of the etching depth of 240 nm, the optimal rib waveguide width was 600 nm and the thickness of the slab layer was 100 nm. By optimizing the doping concentration and the positions of the doping regions, an optimal overall performance of the modulator was obtained. The modulator operated with the static extinction ratio of23.8 dB, the optical loss of 5.34 dB/cm, the modulation efficiency of 2.86 V·cm and the 3 dB EO bandwidth of27.1 GHz at the reverse bias of 4 V. Besides, compared with the device with the top silicon thickness of 220 nm,the overall performance of the modulator was more superior. The research content provides a basis of the device tape-out, and also provides a new idea for the design of the modulator required for the 2 μm band optical transceiver integrated module.