Mode division multiplexing (MDM) technology is becoming increasingly important for modern optical communication systems. Here, an ultra-compact broadband in-line mode converter for quasi-TE ₀₀ and quasi-TE ₁₀ on the silicon-on-insulator platform is proposed and demonstrated experimentally. In our device, the mode-conversion region consists of a continuously width-modulated waveguide with a footprint size as small as 1.32 × 4.52 μm ² . Its modulation profile is designed by using the particle swarm optimization algorithm. This device has a simulated conversion efficiency of about −0.174 dB and an insertion loss less than 0.153 dB within 100-nm wavelength bandwidth from 1500 nm to 1600 nm. Our design exhibits a favorable fabrication error tolerance and the fabricated device has achieved nearly the same conversion efficiency as the simulated one. Our concept can also be applied to design other high-performance mode converters, i.e., converting modes between quasi-TE ₂₀ and quasi-TE ₀₀ . Our work suggests a very promising path for realizing compact integrated MDM systems.

中文翻译：

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基于宽度调制硅波导的超紧凑型宽带串联模式转换器

模分复用（MDM）技术对于现代光通信系统变得越来越重要。在此，提出并通过实验证明了用于绝缘体上硅平台上的准TE ₀₀和准TE ₁₀的超紧凑型宽带串联模式转换器 。在我们的装置中，所述模式转换区由具有足迹尺寸尽可能小的连续宽度调制波导的作为1.32×4.52微米 ² 。通过使用粒子群优化算法设计其调制轮廓。该器件的模拟转换效率约为-0.174 dB，在1500 nm至1600 nm的100 nm波长带宽内的插入损耗小于0.153 dB。我们的设计具有良好的制造误差容限，并且所制造的器件已实现了与模拟器件几乎相同的转换效率。我们的概念也可以应用于设计其他高性能模式转换器，即在准TE ₂₀和准TE ₀₀之间转换模式 。我们的工作为实现紧凑的集成MDM系统提供了非常有希望的途径。