Kondiparthi, Mahesh (2010) High sensitive Static fiber Bragg grating strain sensing using lasers locked to relative frequency reference. In: Conference on Fiber Optic Sensors and Applications VII, APR 07-08, 2010, Orlando, FL,.
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A novel high sensitive fiber Bragg grating (FBG) strain sensing technique using lasers locked to relative frequency reference is proposed and analyzed theoretically. Static strain on FBG independent of temperature can be measured by locking frequency of diode laser to the mid reflection frequency of matched reference FBG, which responds to temperature similar to that of the sensor FBG, but is immune to strain applied to the same. Difference between light intensities reflected from the sensor and reference FBGs (proportional to the difference between respective pass band gains at the diode laser frequency) is not only proportional to the relative strain between the sensor and reference FBGs but also independent of servo residual frequency errors. Usage of relative frequency reference avoids all complexities involved in the usage of absolute frequency reference, hence, making the system simple and economical. Theoretical limit for dynamic and static strain sensitivities considering all major noise contributions are of the order of 25 (p epsilon) / root Hz and 1.2 n epsilon / root Hz respectively.
|Item Type:||Conference Paper|
|Additional Information:||Copyright of this article belongs to he International Society for Optical Engineering.|
|Keywords:||Static strain; Relative frequency reference; matched fiber Bragg grating; servo; Residual frequency error|
|Department/Centre:||Division of Physical & Mathematical Sciences > Instrumentation and Applied Physics (Formally ISU)|
|Date Deposited:||07 Mar 2011 06:37|
|Last Modified:||07 Apr 2011 07:06|
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