Departmental Papers (ESE)


High-refractive-index semiconductor optical waveguides form the basis for modern photonic integrated circuits (PICs). However, conventional methods for achieving optical confinement require a thick lower-refractive-index support layer that impedes large-scale co-integration with electronics and limits the materials on which PICs can be fabricated. To address this challenge, we present a general architecture for single-mode waveguides that confine light in a high-refractive-index material on a native substrate. The waveguide consists of a high-aspect-ratio fin of the guiding material surrounded by lower-refractive-index dielectrics and is compatible with standard top-down fabrication techniques. This letter describes a physically intuitive, semi-analytical, effective index model for designing fin waveguides, which is confirmed with fully vectorial numerical simulations. Design examples are presented for diamond and silicon at visible and telecommunications wavelengths, respectively, along with calculations of propagation loss due to bending, scattering, and substrate leakage. Potential methods of fabrication are also discussed. The proposed waveguide geometry allows PICs to be fabricated alongside silicon CMOS electronics on the same wafer, removes the need for heteroepitaxy in III-V PICs, and will enable wafer-scale photonic integration on emerging material platforms such as diamond and SiC.

Document Type

Journal Article

Date of this Version


Publication Source

APL Photonics



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Copyright/Permission Statement

This is a copy of an article published in APL Photonics, which is available online at:

©2016 Richard R. Grote & Lee C. Bassett

All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (


Waveguides, Diamond, Integrated Photonics

Bib Tex

@ARTICLE{Grote2016, author = {Grote, Richard R. and Bassett, Lee C.}, title = {Single-mode optical waveguides on native high-refractive-index substrates}, journal = {APL Photonics}, year = {2016}, volume = {1}, pages = {071302}, number = {7}, eid = {071302}, doi = {}, owner = {Lee}, timestamp = {2016.09.11}, url = {} }



Date Posted: 03 April 2017

This document has been peer reviewed.