Fabry-Perot cavities based on chemical etching for high temperature and strain sensing

• Type: Article in International Conference Proceedings Book
• Date: 2011

Authors

Paula A R Tafulo (Author) Other; Jorge, PAS (Author) FCUP; Santos, JL (Author) FCUP; Frazao, O (Author) FCUP

Conference proceedings International

Title: International Conference on Applications of Optics and Photonics

International Conference on Applications of Optics and Photonics

Braga, Portugal, 3 a 7 de Maio de 2011

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 2 Citations

Scientific classification

FOS: Engineering and technology > Electrical engineering, Electronic engineering, Information engineering

Other information

Authenticus ID: P-002-X99

DOI: 10.1117/12.892090

Abstract (EN): In this paper, two novel hybrid multimode/single mode fiber Fabry-Perot (FP) cavities were compared. The cavities fabricated by chemical etching are presented as high temperature and strain sensors. In order to produce this FP cavity a single mode fiber was spliced to a graded index multimode fiber with 62.5 mu m core diameter. The multimode fiber was cut approximately 150 mu m away from the splice. Then the tip of the fiber containing the multimode fiber segment was dipped into a solution of 48% of HF during 8 minutes, creating a concavity due to the fact that the reaction between HF and the germanium doped fiber core is much faster than the reaction between HF and the pure silica cladding. By this method a concavity of approximately 100 mu m deep was created at the fiber tip. Two different FP cavities can be fabricated. The first cavity is obtained when a spliced with an identical tip concavity fiber (Sensor A) and the second is created when a tip concavity is spliced to a single mode fiber (Sensor B). The Fabry-Perot cavities were tested as a high temperature sensor in the range between room temperature and 800 degrees C and as strain sensors. A reversible shift of the interferometric peaks with temperature allowed to estimate a sensitivity of 0.75 +/- 0.03 pm/degrees C and 0.98 +/- 0.04 pm/degrees C for the sensor A and B respectively. For strain measurement sensor A demonstrated a sensitivity of 1.85 +/- 0.07 pm/mu epsilon and sensor B showed a sensitivity of 3.14 +/- 0.05 pm/mu epsilon. The sensors demonstrated the feasibility of low cost fiber optic sensors for high temperature and strain.

Language: English

Type (Professor's evaluation): Scientific