Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Charge and topography patterned lithium niobate provides physical cues to fluidically isolated cortical axons
KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum Electronics and Quantum Optics, QEO.ORCID iD: 0000-0001-7242-7300
Show others and affiliations
2017 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 110, no 5, article id 053702Article in journal (Refereed) Published
Abstract [en]

In vitro devices that combine chemotactic and physical cues are needed for understanding how cells integrate different stimuli. We explored the suitability of lithium niobate (LiNbO3), a transparent ferroelectric material that can be patterned with electrical charge domains and micro/ nanotopography, as a neural substrate. On flat LiNbO3 z-surfaces with periodically alternating charge domains, cortical axons are partially aligned with domain boundaries. On submicron-deep etched trenches, neurites are aligned with the edges of the topographical features. Finally, we bonded a bicompartmental microfluidic chip to LiNbO3 surfaces patterned by etching, to create isolated axon microenvironments with predefined topographical cues. LiNbO3 is shown to be an emerging neuron culture substrate with tunable electrical and topographical properties that can be integrated with microfluidic devices, suitable for studying axon growth and guidance mechanisms under combined topographical/chemical stimuli.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2017. Vol. 110, no 5, article id 053702
Keywords [en]
Axons, Topography, Fluidic devices, Etching, Atomic force microscopy
National Category
Other Physics Topics
Identifiers
URN: urn:nbn:se:kth:diva-203961DOI: 10.1063/1.4975304ISI: 000394057600046Scopus ID: 2-s2.0-85011317245OAI: oai:DiVA.org:kth-203961DiVA, id: diva2:1083290
Funder
Swedish Research Council, 622-2010-526Swedish Research Council, 621-2014-5407
Note

QC 20170406

Available from: 2017-03-20 Created: 2017-03-20 Last updated: 2018-10-04Bibliographically approved
In thesis
1. Integrated Nanophotonic Devices in Lithium Niobate
Open this publication in new window or tab >>Integrated Nanophotonic Devices in Lithium Niobate
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Lithium niobate (LN) is a ferroelectric crystal offering a broad transparency spectrum, together with excellent electro-optic and nonlinear optical properties. Thanks to them, LN is setting the standard for quantum optics and telecommunications in critical applications such as ultrafast modulation and frequency conversion. The development of a reliable nanophotonic platform in LN can be expected to effectively leverage all such appealing functionalities in compact and integrated formats and provide important and complementary functionalities to current silicon-photonics platforms.

This thesis encompasses systematic and consistent efforts with the goal to achieve the key building blocks for a comprehensive integrated nanophotonic platform in LN. It involves work on the technology side, sustained and complemented by modelling and experiments, ultimately leading to the demonstration of a few novel devices.

Ultrahigh field confinement in nanophotonic waveguides is accompanied by the appearance of non-negligible longitudinal components in the guided optical fields. By fabricating high-quality LN nanopillars and analyzing with theory and experiments their second harmonic generation (SHG) response, we provide evidence for the existence of longitudinal field components and demonstrate the possibility to reshape the SHG polar emission properties of these submicrometric waveguides by fine-tuning the nanopillar size.

This thesis also presents a different technological approach, allowing the fabrication of photonic wires as small as 250 nm with lengths up to 1 cm on LN-on-insulator (LNOI), suitable for upscaling to photonic integrated circuit (PIC) architectures. By optimizing the fabrication process, the propagation losses of single-mode waveguides at telecom wavelengths on this platform were brought down from 76 to 1.13 dB/cm. Fine-pitch waveguide structuring was also successfully achieved, enabling LNOI-to-fiber grating couplers and waveguide Bragg gratings, the latter featuring record extinction ratios in LNOI (45 dB), comparable to the state of the art in silicon.

The thesis involves also theoretical work on the design of photonic wires where the interplay between LN and waveguide birefringence is used to achieve polarization-insensitive operation for the fundamental guided modes.

Finally, two demonstrators are provided for novel and emerging applications of LN to the life sciences, using LNOI surface-patterned templates for enhanced Raman spectroscopy and LN templates for controlled neuron growth and manipulation in microfluidic environments, respectively.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2018. p. 92
Series
TRITA-SCI-FOU ; 2018:44
Keywords
Lithium niobate (LN), LN-on-insulator, photonic integrated circuits, nonlinear optics, electro-optics, waveguides, propagation losses, Bragg gratings, grating couplers, polarization-insensitive, LN for life sciences
National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:kth:diva-235753 (URN)978-91-7729-977-6 (ISBN)
Public defence
2018-10-26, FA32, Roslagstullsbacken 21, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20181004

Available from: 2018-10-04 Created: 2018-10-04 Last updated: 2018-10-04Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopushttp://aip.scitation.org/doi/10.1063/1.4975304

Authority records BETA

Baghban, Mohammad AminGallo, Katia

Search in DiVA

By author/editor
Baghban, Mohammad AminGallo, Katia
By organisation
Quantum Electronics and Quantum Optics, QEO
In the same journal
Applied Physics Letters
Other Physics Topics

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 81 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf