News and highlighted research topics

Laser restructuring and photoluminescence of glass-clad GaSb/Si-core optical fibres

S. Song, K. Lønsethagen, F. Laurell, T. Hawkins, J. Ballato, M. Fokine, and U. J. Gibson

Nature Communications 10, Article number: 1790 (2019)

Semiconductor-core optical fibres have potential applications in photonics and optoelectronics and mixtures of light-emitting and light-transmitting fibres open up a whole new area of study. In this paper we demonstrate the use of lasers to segregate two materials on a micron scale.

Crystalline GaSb-core optical fibers with room-temperature photoluminescence

S. Song, N. Healy, S. Svendsen, U.L. Østerberg, A.C. Cuervo, J. Liu, A. Peacock, J. Ballato, F. Laurell, M. Fokine, U. Gibson

Optical Materials Express, Vol. 8, Issue 6, pp.1435-1440 (2018)

Glass clad GaSb fibres were shown to emit light even at room temperature and to have crystalline structure.

Laser structuring, stress modification and Bragg grating inscription in silicon-core glass fibers

M. Fokine, A. Theodosiou, S. Song, T. Hawkins, J. Ballato, K. Kalli, & U.J. Gibson

Optical Materials Express, Vol. 7, Issue 5, pp.1589-1597 (2017)

In this paper we demonstrate the laser writing of small period gratings. They are useful for development of sensors in semiconductor core fibres inheriting larger transmission windows than glass-core fibres.

Laser recrystallization and inscription of compositional microstructures in crystalline SiGe-core fibres

D. A. Coucheron, M. Fokine, N. Patil, D. W. Breiby, O. T. Buset, N. Healy, A. C. Peacock, T. Hawkins, M. Jones, J. Ballato, and U. J. Gibson,

Nature Communications 7, Article number: 13265 (2016)

Glass clad fibers with an alloy semiconductor core were shown to have interesting crystallization and transmission properties and displayed the potential of these structures for fundamental materials science studies.

CO₂ Laser-Induced Directional Recrystallization to Produce Single Crystal Silicon-Core Optical Fibers with Low Loss

N. Healy, M. Fokine, Y. Franz, T. Hawkins, M. Jones, J. Ballato, A. C. Peacock, and U. J. Gibson,

Adv. Opt. Mater., Vol. 4, Issue 7, pp.1004–1008 (2016)

Directional recrystallization of silicon-core glass clad fibers has resulted in fibers with single crystal cores over the entire scanned region and dramatically reduced optical losses.
Suppression of nucleation due to the high cooling rate and the quasi-1D geometry are thought to be responsible for the formation of these long single crystals. As internal grain boundaries typically contain both atomic defects and high impurity levels, the recrystallization process leads directly to low optical losses, and holds promise for the production of silicon fibers for signal processing and other applications.