Laser nano-filament explosion for enabling open-grating sensing in optical fibre.

Autor: Mahmoud Aghdami, Keivan, Rahnama, Abdullah, Ertorer, Erden, Herman, Peter R.
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Zdroj: Nature Communications; 11/3/2021, Vol. 12 Issue 1, p1-10, 10p
Abstrakt: Embedding strong photonic stopbands into traditional optical fibre that can directly access and sense the outside environment is challenging, relying on tedious nano-processing steps that result in fragile thinned fibre. Ultrashort-pulsed laser filaments have recently provided a non-contact means of opening high-aspect ratio nano-holes inside of bulk transparent glasses. This method has been extended here to optical fibre, resulting in high density arrays of laser filamented holes penetrating transversely through the silica cladding and guiding core to provide high refractive index contrast Bragg gratings in the telecommunication band. The point‐by‐point fabrication was combined with post-chemical etching to engineer strong photonic stopbands directly inside of the compact and flexible fibre. Fibre Bragg gratings with sharply resolved π-shifts are presented for high resolution refractive index sensing from n H = 1 to 1.67 as the nano-holes were readily wetted and filled with various solvents and oils through an intact fibre cladding. Engineered stop bands to sense an ambient environment can enable many applications. Here, the authors demonstrate well-controlled processes to open high-aspect ratio nanoholes through optical fibre for Bragg gratings in the telecomm spectrum and to enable high-resolution refractive index sensing [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index