Theoretical analysis of mode conversion by refractive-index perturbation based on a single tilted slot on a silicon waveguide

Optics Express
Chia-Chih Huang, Chia-Chien Huang

Abstract

We propose a compact mode converter operating at the mid-infrared wavelength of 3.4 µm, comprising an etched parallelogram slot filled with silicon nitride on a silicon-on-calcium fluoride platform. The tilted slot introduces transverse and longitudinal index perturbations on the waveguide eigenmodes, achieving mode conversion in the propagation direction. Differing from previous reports using massive parameter sweep, we provide analytical formulas to determine geometry parameters by considering the modified phase-matching condition and the profiles of coupling coefficient of coupled-mode theory. Rigorous 3D numerical examples demonstrate the transverse electric (TE)0-to-TE1, TE0-to-TE2, TE0-to-TE3, and TE0-to-TE4 converters to achieve conversion efficiencies (inter-modal crosstalk [CT] values) of >92.7% (<-27 dB), >91.7% (<-16 dB), >88.2% (<-13 dB), and >75.8% (<-10 dB), respectively, with a total transmitted power of >93%. Converter device lengths range from 16.84 to 24.61 µm for TE0-to-TE1 to TE0-to-TE4, respectively. Over a broadband wavelength of 100 nm, the conversion efficiency, power transmission, and maximum inter-modal CT are almost >80%, >90%, and <-10 dB, respectively. Also, the fabrication tolerance of the proposed...Continue Reading

References

Aug 4, 2005·Optics Letters·Gang Chen, Jin U Kang
May 27, 2006·Science·Ulf Leonhardt
May 27, 2006·Science·J B PendryD R Smith
Jul 1, 2010·Optics Express·Tom Baehr-JonesMichael Hochberg
Dec 25, 2012·Optics Express·Mackenzie A Van CampWilliam M J Green
Apr 3, 2013·Optics Letters·Yang XiaQianfan Xu
Jan 16, 2014·Nature Communications·Lian-Wee LuoMichal Lipson
Aug 6, 2014·Nature Nanotechnology·Ricardo GarciaElisa Riedo
Nov 18, 2014·Optics Express·David Ohana, Uriel Levy
Jun 16, 2015·Optics Express·Jing WangMinghao Qi
Oct 31, 2017·ACS Nano·Yu Kyoung Ryu ChoArmin W Knoll
Dec 15, 2018·Optics Letters·A OsmanG Z Mashanovich
Feb 9, 2019·Optics Express·Rulei XiaoXiangfei Chen
Dec 28, 2019·Optics Express·Zhuo ChengXiaomin Ren

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