University of Limerick

Steffen Lochmann

Gabriel Leen

Elfed Lewis

Kort Bremer

Brian J Moss

Ingo Mueller

A pressure sensor (for medical applications comprises a silica optical fiber extrinsic Fabry-Perot interferometric (EFPI) pressure sensor () and an in-fiber Bragg grating (FBG,). The cavity of the EFPI pressure sensor () is formed by the end face of the FBG (), a glass capillary () and a glass diaphragm (). The glass diaphragm () is secured in place by a fusion splice () and the glass capillary () by a fusion splice (). As illustrated, incident light is directed into the FBGand there are reflections in the EFPI pressure sensor (). Applied pressure causes a deflection of the glass diaphragm () and hence modulation of the EFPI sensor () cavity. The FBG () is used as a reference sensor to eliminate temperature cross-sensitivity of the EFPI pressure sensor (). The EFPI cavity was fabricated using a 200 &#x3bc;m silica glass fiber, a 133/220 &#x3bc;m (inner/outer diameter) silica glass capillary and a standard telecommunication FBG. Initially, the end faces of the 200 &#x3bc;m silica glass fiber and the silica glass capillary were polished and both planar surfaces were spliced together using a fusion splicer. Then the silica glass capillary was cleaved 5 mm away form the capillary/200 &#x3bc;m fiber splice. After that, the FBG () was inserted into the silica glass capillary () and both elements were bonded together using the fusion splicer again.

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Dahlewitz, Germany

Steffen Lochmann