University of Limerick

Aktiebolaget Skf

Bluepoint Medical Gmbh & Co. Kg

Elfed Lewis

Florin Tatar

Martin Degner

Hartmut Ewald

Gabriel Leen

Romain Herdier

Sven Poeggel

Kort Bremer

Dinesh Babu Duraibabu

Brian J Moss

Steffen Lochmann

Ingo Mueller

Thomas Reinsch

Gerard Dooly

Nils Damaschke

A temperature sensor () has a pressure sensor (), the distal end of which is inserted in a sealed chamber () filled with a liquid. The pressure sensor has a light guide (), a cavity () at a distal end of the light guide, a diaphragm () forming a wall of the cavity and being configured to deflect with applied pressure, and a detector to detect changes in light reflection due to deflection of the diaphragm. The liquid () which changes volume in response to temperature changes and this volume change is sufficient to change the pressure applied on the diaphragm (), and the a interrogation system processes pressure data and/or light reflection data to generate an output indicating temperature of the fluid in the chamber.

Temperature sensor

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.

Pressure sensor with an interferometric sensor and an in-fiber bragg grating reference sensor

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County Clare, Ireland

Elfed Lewis