Cao Wei, Liu Shenghao, Littlejohns Callum G, Thomson David J, Nedeljkovic Milos, Zhang Weiwei, Li Ke, Banakar Mehdi, Tran Ying, Yan Xingzhao, Du Han, Ren Zhengqi, Gardes Frederic, Reed Graham T, Mashanovich Goran Z
Opt Express. 2021 May 10;29(10):14438-14451. doi: 10.1364/OE.418285.
We demonstrate high-speed silicon modulators optimized for operating at the wavelength of 2 μm. The Mach-Zehnder interferometer (MZI) carrier-depletion modulator with 2 mm phase shifter has a single-arm modulation efficiency (V ·L) of 2.89 V·cm at 4 V reverse bias. Using a push-pull configuration it operates at a data rate of 25 Gbit/s OOK with an extinction ratio of 6.25 dB. We also proposed a mathematically-analysed streamlined IMDD PAM-4 scheme and successfully demonstrated a 25 Gbit/s datarate PAM-4 with the same 2 mm modulator. A Michelson interferometer carrier-depletion modulator with 0.5 mm phase shift length has also been shown with modulation efficiency (V ·L) of 1.36 V·cm at 4 V reverse bias and data rate of 20 Gbit/s OOK. The Michelson interferometer modulator performs similarly to a Mach-Zehnder modulator with twice the phase shifter length.
我们展示了针对在2μm波长下运行而优化的高速硅调制器。具有2mm移相器的马赫曾德尔干涉仪（MZI）载流子耗尽调制器在4V反向偏置下的单臂调制效率（V·L）为2.89V·cm。采用推挽配置时，它以25Gbit/s的归零码（OOK）数据速率运行，消光比为6.25dB。我们还提出了一种经过数学分析的简化强度调制直接检测（IMDD）脉冲幅度调制（PAM-4）方案，并成功展示了使用相同2mm调制器实现的25Gbit/s数据速率的PAM-4。还展示了具有0.5mm相移长度的迈克尔逊干涉仪载流子耗尽调制器，其在4V反向偏置下的调制效率（V·L）为1.36V·cm，归零码（OOK）数据速率为20Gbit/s。迈克尔逊干涉仪调制器的性能与相移器长度为其两倍的马赫曾德尔调制器相似。
