Temperature insensitive fiber coil sensor for altimeters.
A displacement sensor using a pair of flat Panda fiber coils with a 90 degrees connection is demonstrated. The dual coils are squeezed differentially. The phase retardations caused by the compression are constructively added, while the retardations caused by the environmental temperature are destructively added, thereby removing the temperature effect. Both the birefringence and loss effects induced by the deformation of the coils are utilized for high accuracy detection and emergency detection, respectively. In experiments using thirty turn coils, the guaranteed sensitivity of 357 degrees /mm (retardation/displacement) and the long term stability of 4 degrees /h (retardation/period) were obtained.
Imai
Y
Y
Rodorigues
M A
MA
Lizuka
K
K