The DFB fiber laser strain sensor is shown to provide an improvement in the minimum detectable length change by a factor of 275 at 2 kHz for an applied strain when compared with an interferometric sensor interrogated by an equivalent DFB laser. This corresponds to a strain resolution enhancement by a factor of 18, if the strain is applied over a 10cm length of fiber. The ability of the fiber laser sensor to operate in its thermodynamic noise limit is shown to be the primary reason for this enhanced sensitivity. Thermodynamically limited noise performance is demonstrated with three interrogation methods.
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