A semi-empirical integrated microring cavity approach for 2D material optical index identification at 1.55 μm

Nanophotonics

article

Rishi Maiti¹  Ludwig Bartels²  Volker J. Sorger¹  Rohit A. Hemnani¹  Rubab Amin¹  Zhizhen Ma¹  Mohammad H. Tahersima¹  Tom A. Empante²  Hamed Dalir³  Ritesh Agarwal⁴ 

[1] Department of Electrical and Computer Engineering, George Washington University;Chemistry and Materials Science and Engineering, University of California;Inc.;Department of Materials Science and Engineering, University of Pennsylvania

关键词: heterogeneous integration;    2D materials;    TMDCs;    microring resonator;    2D printer;    coupling coefficients;   

DOI  :  10.1515/nanoph-2018-0197

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Atomically thin 2D materials such as transition metal dichalcogenides (TMDs) provide a wide range of basic building blocks with unique properties, making them ideal for heterogeneous integration with a mature chip platform for advances in optical communication technology. The control and understanding of the precise value of the optical index of these materials, however, is challenging, as the standard metrology techniques such as the millimeter-large ellipsometry is often not usable due the small lateral 2D material flake dimension. Here, we demonstrate an approach of passive tunable coupling by integrating few layers of MoTe 2 onto a microring resonator connected to a waveguide bus. We find the TMD-to-ring circumference coverage length ratio required to precisely place the ring into a critical coupling condition to be about 10% as determined from the variation of spectral resonance visibility and loss as a function of TMD coverage. Using this TMD-ring heterostructure, we further demonstrate a semiempirical method to determine the index of a 2D material ( n MoTe2 of 4.36+0.011 i ) near telecommunication-relevant wavelength. The placement, control, and optical property understanding of 2D materials with integrated photonics pave the way for further studies of active 2D material-based optoelectronics and circuits.

【 授权许可】

CC BY