|Publication No: 2370||Search all ORC publications|
Material optimisation for high-temperature grating devices written by KrF excimer lasers
G.Brambilla, T.P.Newson and H.Rutt
We have studied the thermal stability of gratings written in fibres of different composition using a 248 nm KrF excimer laser. Measurements up to ~800 °C confirm the long-term thermal stability of Bragg-gratings written in tin-doped silica fibres and demonstrate a significant advantage over gratings written in conventional photosensitive fibres.
Optical fibre devices have minimal intrusion and considerable advantages in hostile environments, such as in the presence of high electric, magnetic or strong RF fields . Bragg-gratings can be used as a possible transducer for temperature measurements , as an alternative to the use of fluorescence emission from rare earth-doped and transition metal-doped fibres [3-41. Bragg-gratings can also be used to measure many other physical parameters including strain [5,6] and pressure [7,8]. Moreover, grating sensors can be multiplexed in arrays along a single fibre, thus sampling the spatial distribution of a parameter or simultaneously measuring several different parameters . However, fibre gratings written in conventional fibres exhibit poor stability at high temperatures, especially if produced using the hydrogen-loading technique. In this paper, we compare the thermal stability of Bragg-gratings written in the tin-doped fibres recently developed at the University of Southampton  with three conventional fibres up to a temperature of approximately 800 °C.
IoP meeting on 'In-fibre Gratings and Special Fibres' - Photonex 2001 Coventry 17-Oct (2001)
Copyright University of Southampton 2006