Effects of coating and diametric load on fiber Bragg gratings as cryogenic temperature sensors

Meng-Chou Wu; Ruth H. Pater; Stanton L. DeHaven

doi:10.1117/12.775895

27 March 2008 Effects of coating and diametric load on fiber Bragg gratings as cryogenic temperature sensors

Meng-Chou Wu, Ruth H. Pater, Stanton L. DeHaven

Proceedings Volume 6933, Smart Sensor Phenomena, Technology, Networks, and Systems 2008; 693303 (2008) https://doi.org/10.1117/12.775895
Event: SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, 2008, San Diego, California, United States

Abstract

Cryogenic temperature sensing was demonstrated using pressurized fiber Bragg gratings (PFBGs) with polymer coating of various thicknesses. The PFBG was obtained by applying a small diametric load to a regular fiber Bragg grating (FBG). The Bragg wavelengths of FBGs and PFBG were measured at temperatures from 295 K to 4.2 K. The temperature sensitivities of the FBGs were increased by the polymer coating. A physical model was developed to relate the Bragg wavelength shifts to the thermal expansion coefficients, Young's moduli, and thicknesses of the coating polymers. When a diametric load of no more than 15 N was applied to a FBG, a pressure-induced transition occurred at 200 K during the cooling cycle. The pressure induced transition yielded PFBG temperature sensitivities three times greater than conventional FBGs for temperatures ranging from 80 to 200 K, and ten times greater than conventional fibers for temperatures below 80 K. PFBGs were found to produce an increased Bragg wavelength shift of 2.2 nm compared to conventional FBGs over the temperature range of 4.2 to 300 K. This effect was independent of coating thickness and attributed to the change of the fiber thermo-optic coefficient.

Citation Download Citation

Meng-Chou Wu, Ruth H. Pater, and Stanton L. DeHaven "Effects of coating and diametric load on fiber Bragg gratings as cryogenic temperature sensors", Proc. SPIE 6933, Smart Sensor Phenomena, Technology, Networks, and Systems 2008, 693303 (27 March 2008); https://doi.org/10.1117/12.775895

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available