CaltechAUTHORS
  A Caltech Library Service

Fabrication of ultra-thin si nanopillar arrays for polarization-independent spectral filters in the near-IR

Ng, Ryan C. and Greer, Julia R. and Fountaine, Katherine T. (2018) Fabrication of ultra-thin si nanopillar arrays for polarization-independent spectral filters in the near-IR. In: Photonic and Phononic Properties of Engineered Nanostructures VIII. Proceedings of SPIE. No.10541. Society of Photo-optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 105411D. ISBN 9781510615670. http://resolver.caltech.edu/CaltechAUTHORS:20190110-080648684

[img] PDF - Published Version
See Usage Policy.

643Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20190110-080648684

Abstract

Sub-wavelength arrays have garnered significant interest for many potential optoelectronics applications. We fabricated sub-wavelength silicon nanopillar arrays with a ratio of radius, r and a center-to-center distance, a, of r/a ≈ 0.2 that were fully embedded in SiO_2 for narrow stopband filters that are compact and straightforward to fabricate compared to conventional Bragg stack reflectors. These arrays are well-suited for hyperspectral filtering applications in the infrared. They are ultra-thin (<0.1λ), polarization-independent, and attain greater efficiencies enabled by low loss compared to plasmonic-based designs. The choice of Si as the nanopillar material stems from its low cost, high index of refraction, and a band gap of 1.1 eV near the edge of the visible. These arrays exhibit narrow near-unity reflectivity resonances that arise from coupling of an incident wave into a leaky waveguide mode via a grating vector that is subsequently reradiated, also known as guided mode resonances (GMRs). Simulations reveal reflectivities of >99% with full width at half maxima (FWHM) of ≈0.01 μm. We demonstrate a fabrication route for obtaining nanopillar arrays that exhibit these GMRs. We experimentally observed a GMR with an amplitude of ~0.8 for filter arrays fabricated on silicon on insulator (SOI) substrates, combined with Fabry-Perot interference that stems from the underlying silicon layer.


Item Type:Book Section
Related URLs:
URLURL TypeDescription
https://doi.org/10.1117/12.2286804DOIArticle
ORCID:
AuthorORCID
Greer, Julia R.0000-0002-9675-1508
Fountaine, Katherine T.0000-0002-0414-8227
Additional Information:© 2018 Society of Photo-optical Instrumentation Engineers (SPIE).
Subject Keywords:nanopillar array, guided mode resonance, spectral filters
Record Number:CaltechAUTHORS:20190110-080648684
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20190110-080648684
Official Citation:Ryan C. Ng, Julia R. Greer, Katherine T. Fountaine, "Fabrication of ultra-thin Si nanopillar arrays for polarization-independent spectral filters in the near-IR," Proc. SPIE 10541, Photonic and Phononic Properties of Engineered Nanostructures VIII, 105411D (21 February 2018); doi: 10.1117/12.2286804
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:92190
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:10 Jan 2019 20:33
Last Modified:10 Jan 2019 20:33

Repository Staff Only: item control page