Long-term stability decay of standard and regenerated Bragg gratings tailored for high temperature operation

• Main Authors: F. K. Coradin, V. de Oliveira, M. Muller, H. J. Kalinowski, J. L. Fabris
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo
• Series: Journal of Microwaves, Optoelectronics and Electromagnetic Applications
• Subjects: Bragg sensors; High temperature; Decay stability
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2179-10742013000200038&lng=en&tlng=en

Thermal stability of both standard and regenerated Bragg gratings written in normal and photosensitive optical fibers was accessed. An apparent spectral wavelength stabilization of common gratings with no thermal hysteresis was reached after thermal treatments. However, after a time interval of 5 months, gratings exhibited a shift in the resonance Bragg wavelength at room temperature, as well as important changes in the thermal sensitivity above 200 ºC. Regenerated gratings proved to be stable only at temperatures below the critical regeneration temperature, with significant loss of reflectivity above that critical value.