硅光子模斑转换器是硅光子集成芯片与外部光纤连接的关键器件,在集成光路中起着至关重要的作用。标准光纤的模斑尺寸与纳米光子波导的模斑尺寸不匹配,导致标准光纤与纳米级硅波导直接对接时存在很大的耦合损耗,而硅光子模斑转换器能够显著减小它们之间的光损耗。硅光子模斑转换器的一端具有较大的模斑尺寸,与标准光纤的模斑尺寸相匹配;其另一端具有较小的模斑尺寸,与纳米硅光子波导的模斑尺寸相匹配,因此能够显著减小标准光纤与纳米硅光子波导之间的光连接损耗。综述了不同结构转换器的特点,对不同类型的转换器在结构、性能以及应用上的优缺点进行了比较与分析,对硅光子模斑转换器的前景进行了展望,并提出一些看法。

Silicon photonic mode size converter is the key device for silicon based photonic integrated chip to connect with external optical fiber, it plays an important role in integrated optical path. The mode size of the standard fibers does not match the mode size of the nanometer photonic waveguide, so there is a great coupling loss between the standard fiber and the nanometer silicon waveguide, the silicon photonic mode size converters can significantly reduce the optical loss between them. One end of the silicon based photonic mode size converter has a large mode size that matches with the mode size of the standard fiber; the other end has a smaller mode size, which can be matched with the mode size of nano-silicon photonic waveguide, thereby significantly reducing the optical connection loss between the standard fiber and the nano-silicon photonic waveguide. The characteristics of different structures of converters are reviewed, while the advantages and disadvantages of different types of converters in structure, performance and application are compared and analyzed, and the prospect of silicon photonic mode size converters is prospected and some opinions are put forward.