Multipoint fibre-optical temperature sensor

Abstract

Abstract The sensor uses the effect of the variation in birefringence with respect to temperature in a doubly refracting optical fibre. <??>It consists of a linearly polarised broad-spectrum source (10) coupled to a single-mode optical fibre with conservation of polarisation (11) along one of its neutral axes, the positions of weak coupling being distributed along this fibre. A polariser (12) at 45 DEG of the neutral axes of the fibre is placed at the output of this sensor fibre. The radiation at the output is analysed by spectroscopic means, e.g. in an adjustable Michelson interferometer (13, 14, 15) combined with a detector (16). The interferometer displacements required to detect the extreme values of the transmission function are measures of the temperature differences. <??>Application to the production of accurate heat sensors with a wide range of variations. <IMAGE>

Inventors

• 👤 Hervé Lefevre
• 👤 Jean-Pierre Bettini
• 👤 Serge Botti
• 👤 Marc Turpin

Bibliographic Details