Groove auxiliary acoustic optical modulator based on a lithium niobate film,

Abstract

The invention discloses a groove auxiliary acoustic optical modulator based on a lithium niobate film. The acoustic optical modulator comprises a lithium niobate film layer, a lithium niobate thin film waveguide and an interdigital transducer, wherein the lithium niobate thin film waveguide and the interdigital transducer are arranged on the lithium niobate thin film layer, and a groove is engraved in the top of the lithium niobate thin film waveguide. As optical waveguide structures adopted in a traditional acoustic optical modulator designed based on a lithium niobate thin film are regular strip-shaped waveguides, and the efficiency of acoustic optical interaction generated by the regular strip-shaped waveguides based on surface acoustic waves is not high; while in the acoustic optical modulator of the invention, the groove is engraved in the top of the lithium niobate thin film waveguide, so that the interaction between a deformation displacement field generated by the lithium niobate film waveguide based on surface acoustic waves and a waveguide optical electromagnetic field can be enhanced, so that the problem of low acoustic optical interaction efficiency in the existing acoustic optical modulator is solved. 本发明公开了一种基于铌酸锂薄膜的凹槽辅助式声光调制器，其中，所述声光调制器包括：铌酸锂薄膜层；设置于所述铌酸锂薄膜层上的铌酸锂薄膜波导和叉指换能器，其中，所述铌酸锂薄膜波导的顶部刻有凹槽。由于传统的基于铌酸锂薄膜设计的声光调制器中采用的光波导结构均为规则的条形波导，规则的条形波导基于表面声波产生的声光互作用效率不高，而本发明在铌酸锂薄膜波导的顶部刻有凹槽，可以增强铌酸锂薄膜波导基于表面声波产生的形变位移场与波导光学电磁场之间的相互作用，从而解决了现有声光调制器中声光互作用效率低的问题。