基于铌酸锂薄膜的三波导偏振分束及模式转换器

Efficient Three-waveguide Based Polarization Splitting and Mode Conversion on Lithium Niobate-on-insulator Platform

铌酸锂单晶薄膜(LNOI)对集成光学的发展有着重要意义,而高效的偏振分束与模式转换器件的设计是集成光学需要解决的一个基本问题。本文在充分考虑铌酸锂薄膜的研究现状及加工工艺的基础上,提出了一种基于铌酸锂薄膜的三波导偏振分束及模式转换器,该器件可将输入的TM0和TE0模式进行高效分离并将TE0模式转换为TE1模式。通过严格的设计与仿真优化,在片上同时实现了高效偏振分离及模式转换的功能。此外,通过增加交叉输出波导的宽度,所述器件方案可进一步扩展至其他高阶TE模的输出,具备良好的器件功能可扩展性。

Lithium niobate-on-insulator(LNOI) is of great significance to the development of integrated photonics,where the efficient polarization splitting and mode conversion is the basic problem to be solved in integrated optics. In this paper, a three-waveguide based polarization splitter and mode converter is proposed under the consideration of current fabrication processes of LNOI. Based on the asymmetrical directional coupling principle, the proposed device can effectively separate TM0 and TE0 modes and convert TE0 mode to TE1 mode simultaneously on the same chip.. Further,the proposed device scheme can be extended to output other higher-order TE modes via adding the width of the cross output waveguide, revealing high functional scalability for the future multiplexing transmission on the LNOI platform.