Optical fibre interferometer
Jaime Pinto Ribeiro Frazão
The present invention refers to an optical fibre interferometer that consists of a multi-mode fibre section spliced between two single-mode fibre sections. The single-mode fibre contains a long period fibre grating so that it is possible to couple the radiation between the core and the cladding. This device is based on multi-modal interference and can be embedded in advanced composite and polymeric materials.
This invention can work as a sensor to measure the radius of a curve in a wide variety of values from just a few centimetres to dozens of meters and with high linearity. It can also be used to measure other physical, chemical and biological parameters, such as temperature, strain, twist and refractive index. Finally, it can be used as an optical filter for fibre optic communication.