Deep-subwavelength plasmonic mode converter with large size reduction for Si-wire waveguide

作者：Ono Masaaki^*; Taniyama Hideaki; Xu Hao; Tsunekawa Masato; Kuramochi Eiichi; Nozaki Kengo; Notomi Masaya

来源：Optica, 2016, 3(9): 999-1005.

DOI：10.1364/OPTICA.3.000999

If we are to utilize deep-subwavelength plasmonic waveguides in photonic integrated circuit applications, highly efficient three-dimensional (3D) mode conversion must be achieved between deep-subwavelength plasmonic waveguides and conventional dielectric waveguides such as Si-wire waveguides. Here, we describe 3D mode conversion from a Si-wire waveguide (the core size is 400 nm x 200 nm) to a plasmonic slot waveguide (the air core size is 50 nm x 20 nm) with a coupling loss of 1.7 dB. Our mode converter has only a two-dimensional laterally tapered structure even with the presence of a large discontinuity in the thickness, and can still produce efficient full 3D mode conversion with a very short taper length (600 nm). Calculation results obtained with the finite element method agreed well with the experimental results. We believe our mode converter will provide a new deep-subwavelength photonic platform.

• 出版日期2016-9-20