Annealing dynamics of waveguide Bragg gratings: evidence of femtosecond laser induced colour centres.
There is still significant speculation regarding the nature of femtosecond laser induced index change in bulk glasses with colour centre formation and densification the main candidates. In the work presented here, we fabricated waveguide Bragg gratings in doped and undoped phosphate glasses and use these as a diagnostic for monitoring subtle changes in the induced refractive index during photo- and thermal annealing experiments. Reductions in grating strengths during such experiments were attributed to the annihilation of colour centres.
Dekker
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P
Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), MQ Photonics Research Centre, Department of Physics and Engineering, Macquarie University, New South Wales, 2109, Australia. dekker@science.mq.edu.au
Ams
M
M
Marshall
G D
GD
Little
D J
DJ
Withford
M J
MJ
D003116:Color; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005898:Glass / Q000737:chemistry* / Q000528:radiation effects*; D007834:Lasers; D012031:Refractometry / Q000295:instrumentation*; D013499:Surface Properties