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

US8764678B2 · kind B2 · utility

Assignee

• University of Limerick · IE

Inventors

• Kort Bremer · Hannover, DE
• Gabriel Leen · Cork, IE
• Elfed Lewis · Ennis, IE
• Brian Moss · Limerick, IE
• Steffen Lochmann · Dahlewitz, DE
• Ingo Mueller · Heidelberg, DE

Key dates

• Filing date: Jan 31, 2011
• Grant date: Jul 1, 2014
• Expiry date: Aug 16, 2032

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49194
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A pressure sensor (10 for medical applications comprises a silica optical fiber extrinsic Fabry-Perot interferometric (EFPI) pressure sensor (2) and an in-fiber Bragg grating (FBG, 3). The cavity of the EFPI pressure sensor (2) is formed by the end face of the FBG (3), a glass capillary (5) and a glass diaphragm (6). The glass diaphragm (6) is secured in place by a fusion splice (7) and the glass capillary (5) by a fusion splice (8). As illustrated, incident light is directed into the FBG 3 and there are reflections in the EFPI pressure sensor (2). Applied pressure causes a deflection of the glass diaphragm (6) and hence modulation of the EFPI sensor (2) cavity. The FBG (3) is used as a reference sensor to eliminate temperature cross-sensitivity of the EFPI pressure sensor (2). The EFPI cavity was fabricated using a 200 μm silica glass fiber, a 133/220 μm (inner/outer diameter) silica glass capillary and a standard telecommunication FBG. Initially, the end faces of the 200 μm 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/2…