Polarimetric Temperature Sensor Using Core-replaced Fiber Polarimetric Temperature Sensor Using Core-replaced Fiber

by Ipson, Benjamin L

Optical fibers are increasingly being used to create sensing devices. The D-fiber has an elliptical core and exhibits birefringence. This birefringence can be used to create a polarimetric sensor. The elliptical core supports two orthogonal modes that have separate effective indices of refraction. The indices of refraction change with a change in temperature. Since the effective indices of refraction change differently for the two modes, the birefringence also changes. This change in birefringence can be seen as a change in detected power through the fiber through the use of polarizers. The fiber then becomes a temperature sensor.

The sensitivity of the fiber can be enhanced by replacing a section of the core of the fiber with a sensing material. With the sensing material in the core of the fiber, it has direct interaction with the light and strongly affects it. A polarimetric temperature sensor is created by replacing a section of the core with a polymer, which is sensitive to temperature. The core-replaced fiber in a polarimetric sensing configuration is compared to a a unetched fiber set up in the same way. The core-replaced fiber sensor is five times as sensitive to temperature as an unetched fiber.