Numerical modelling of interrogation systems for optical fibre Bragg grating sensors

Daniel Oswald; Steven Richardson; Graham Wild

doi:10.1117/12.903544

23 December 2011 Numerical modelling of interrogation systems for optical fibre Bragg grating sensors

Daniel Oswald, Steven Richardson, Graham Wild

Proceedings Volume 8204, Smart Nano-Micro Materials and Devices; 82040Q (2011) https://doi.org/10.1117/12.903544
Event: SPIE Smart Nano + Micro Materials and Devices, 2011, Melbourne, Australia

Abstract

There are a number of interrogation methods that can be used in optical Fibre Bragg Grating (FBG) sensing system. For very high frequency signals interrogating the sensor signal from an FBG is limited to two intensiometric methods, edge filter detection and power detection. In edge filter detection, a broadband light source illuminates an FBG, the reflected spectrum is then passed through a spectral filter. In power detection, a narrowband light source with a wavelength corresponding to the 3dB point of the FBG is filtered by the FBG itself. Both methods convert the spectral shift of the FBG into intensity signals. These two categories each have a number of variations, all with different performance characteristics. In this work we present a numerical model for all of these interrogation systems. The numerical model is based on previous analytical modelling, which could only be utilised for perfect Gaussian profiles. However, interrogation systems can make use of non Gaussian shaped filters, or sources. The numerical modelling enables the different variations to be compared using identical component performance, showing the relative strengths and weakness of the systems in terms of useful parameters, including, signal-to-noise ratio, sensitivity, and dynamic resolution. The two different detection methods can also be compared side-by-side using the same FBG. Since the model is numerical, it enables real spectral data to be used for the various components (FBG, light source, filters). This has the added advantage of increasing the accuracy and usefulness of the model, over previous analytical work.

Citation Download Citation

Daniel Oswald, Steven Richardson, and Graham Wild "Numerical modelling of interrogation systems for optical fibre Bragg grating sensors", Proc. SPIE 8204, Smart Nano-Micro Materials and Devices, 82040Q (23 December 2011); https://doi.org/10.1117/12.903544

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