Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating Structure
This contribution demonstrates photonic crystal waveguides generated within bulk planar sapphire substrates. A femtosecond laser is used to modify the refractive index in a hexagonal pattern around the pristine waveguide core. Near-field measurements reveal single-mode behavior at a wavelength of 15...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Photonics |
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| Online Access: | https://www.mdpi.com/2304-6732/9/4/234 |
| _version_ | 1797409586662080512 |
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| author | Stefan Kefer Gian-Luca Roth Julian Zettl Bernhard Schmauss Ralf Hellmann |
| author_facet | Stefan Kefer Gian-Luca Roth Julian Zettl Bernhard Schmauss Ralf Hellmann |
| author_sort | Stefan Kefer |
| collection | DOAJ |
| description | This contribution demonstrates photonic crystal waveguides generated within bulk planar sapphire substrates. A femtosecond laser is used to modify the refractive index in a hexagonal pattern around the pristine waveguide core. Near-field measurements reveal single-mode behavior at a wavelength of 1550 nm and the possibility to adapt the mode-field diameter. Based on far-field examinations, the effective refractive index contrast between the pristine waveguide core and depressed cladding is estimated to 3·10<sup>−4</sup>. Additionally, Bragg gratings are generated within the waveguide core. Due to the inherent birefringence of Al<sub>2</sub>O<sub>3</sub>, the gratings exhibit two distinct wavelengths of main reflection. Each reflection peak exhibits a narrow spectral full width at a half maximum of 130 pm and can be selectively addressed by exciting the birefringent waveguide with appropriately polarized light. Furthermore, a waveguide attenuation of 1 dB cm<sup>−1</sup> is determined. |
| first_indexed | 2024-03-09T04:17:42Z |
| format | Article |
| id | doaj.art-222540c4614c476b919ea952e4f4e16e |
| institution | Directory Open Access Journal |
| issn | 2304-6732 |
| language | English |
| last_indexed | 2024-03-09T04:17:42Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Photonics |
| spelling | doaj.art-222540c4614c476b919ea952e4f4e16e2023-12-03T13:51:28ZengMDPI AGPhotonics2304-67322022-04-019423410.3390/photonics9040234Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating StructureStefan Kefer0Gian-Luca Roth1Julian Zettl2Bernhard Schmauss3Ralf Hellmann4Applied Laser and Photonics Group, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, GermanyApplied Laser and Photonics Group, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, GermanyApplied Laser and Photonics Group, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, GermanyInstitute of Microwaves and Photonics, University of Erlangen-Nuremberg, Cauerstrasse 9, 91058 Erlangen, GermanyApplied Laser and Photonics Group, Aschaffenburg University of Applied Sciences, Wuerzburger Strasse 45, 63743 Aschaffenburg, GermanyThis contribution demonstrates photonic crystal waveguides generated within bulk planar sapphire substrates. A femtosecond laser is used to modify the refractive index in a hexagonal pattern around the pristine waveguide core. Near-field measurements reveal single-mode behavior at a wavelength of 1550 nm and the possibility to adapt the mode-field diameter. Based on far-field examinations, the effective refractive index contrast between the pristine waveguide core and depressed cladding is estimated to 3·10<sup>−4</sup>. Additionally, Bragg gratings are generated within the waveguide core. Due to the inherent birefringence of Al<sub>2</sub>O<sub>3</sub>, the gratings exhibit two distinct wavelengths of main reflection. Each reflection peak exhibits a narrow spectral full width at a half maximum of 130 pm and can be selectively addressed by exciting the birefringent waveguide with appropriately polarized light. Furthermore, a waveguide attenuation of 1 dB cm<sup>−1</sup> is determined.https://www.mdpi.com/2304-6732/9/4/234integrated photonicssapphireBragg gratingfemtosecond laserphotonic crystal waveguidedepressed cladding |
| spellingShingle | Stefan Kefer Gian-Luca Roth Julian Zettl Bernhard Schmauss Ralf Hellmann Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating Structure Photonics integrated photonics sapphire Bragg grating femtosecond laser photonic crystal waveguide depressed cladding |
| title | Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating Structure |
| title_full | Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating Structure |
| title_fullStr | Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating Structure |
| title_full_unstemmed | Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating Structure |
| title_short | Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating Structure |
| title_sort | sapphire photonic crystal waveguides with integrated bragg grating structure |
| topic | integrated photonics sapphire Bragg grating femtosecond laser photonic crystal waveguide depressed cladding |
| url | https://www.mdpi.com/2304-6732/9/4/234 |
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