Cargando…

Precise and diffraction-limited waveguide-to-free-space focusing gratings

We present the design and characterization of waveguide grating devices that couple visible-wavelength light at λ = 674 nm from single-mode, high index-contrast dielectric waveguides to free-space beams forming micron-scale diffraction-limited spots a designed distance and angle from the grating. Wi...

Descripción completa

Detalles Bibliográficos
Autores principales: Mehta, Karan K., Ram, Rajeev J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5435719/
https://www.ncbi.nlm.nih.gov/pubmed/28515482
http://dx.doi.org/10.1038/s41598-017-02169-2
_version_ 1783237261283819520
author Mehta, Karan K.
Ram, Rajeev J.
author_facet Mehta, Karan K.
Ram, Rajeev J.
author_sort Mehta, Karan K.
collection PubMed
description We present the design and characterization of waveguide grating devices that couple visible-wavelength light at λ = 674 nm from single-mode, high index-contrast dielectric waveguides to free-space beams forming micron-scale diffraction-limited spots a designed distance and angle from the grating. With a view to application in spatially-selective optical addressing, and in contrast to previous work on similar devices, deviations from the main Gaussian lobe up to 25 microns from the focus and down to the 5 × 10(−6) level in relative intensity are characterized as well; we show that along one dimension the intensity of these weak sidelobes approaches the limit imposed by diffraction from the finite field extent in the grating region. Additionally, we characterize the polarization purity in the focal region, observing at the center of the focus a low impurity <3 × 10(−4) in relative intensity. Our approach allows quick, intuitive design of devices with such performance, which may be applied in trapped-ion quantum information processing and generally in any systems requiring optical routing to or from objects 10 s–100 s of microns from a chip surface, but benefitting from the parallelism and density of planar-fabricated dielectric integrated optics.
format Online
Article
Text
id pubmed-5435719
institution National Center for Biotechnology Information
language English
publishDate 2017
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-54357192017-05-18 Precise and diffraction-limited waveguide-to-free-space focusing gratings Mehta, Karan K. Ram, Rajeev J. Sci Rep Article We present the design and characterization of waveguide grating devices that couple visible-wavelength light at λ = 674 nm from single-mode, high index-contrast dielectric waveguides to free-space beams forming micron-scale diffraction-limited spots a designed distance and angle from the grating. With a view to application in spatially-selective optical addressing, and in contrast to previous work on similar devices, deviations from the main Gaussian lobe up to 25 microns from the focus and down to the 5 × 10(−6) level in relative intensity are characterized as well; we show that along one dimension the intensity of these weak sidelobes approaches the limit imposed by diffraction from the finite field extent in the grating region. Additionally, we characterize the polarization purity in the focal region, observing at the center of the focus a low impurity <3 × 10(−4) in relative intensity. Our approach allows quick, intuitive design of devices with such performance, which may be applied in trapped-ion quantum information processing and generally in any systems requiring optical routing to or from objects 10 s–100 s of microns from a chip surface, but benefitting from the parallelism and density of planar-fabricated dielectric integrated optics. Nature Publishing Group UK 2017-05-17 /pmc/articles/PMC5435719/ /pubmed/28515482 http://dx.doi.org/10.1038/s41598-017-02169-2 Text en © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Mehta, Karan K.
Ram, Rajeev J.
Precise and diffraction-limited waveguide-to-free-space focusing gratings
title Precise and diffraction-limited waveguide-to-free-space focusing gratings
title_full Precise and diffraction-limited waveguide-to-free-space focusing gratings
title_fullStr Precise and diffraction-limited waveguide-to-free-space focusing gratings
title_full_unstemmed Precise and diffraction-limited waveguide-to-free-space focusing gratings
title_short Precise and diffraction-limited waveguide-to-free-space focusing gratings
title_sort precise and diffraction-limited waveguide-to-free-space focusing gratings
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5435719/
https://www.ncbi.nlm.nih.gov/pubmed/28515482
http://dx.doi.org/10.1038/s41598-017-02169-2
work_keys_str_mv AT mehtakarank preciseanddiffractionlimitedwaveguidetofreespacefocusinggratings
AT ramrajeevj preciseanddiffractionlimitedwaveguidetofreespacefocusinggratings