All-optical enhancement of minimum detectable perturbation in intensity-based fiber sensors

We present a novel optical signal processing scheme for enhancing the minimum detectable environmental perturbation of intensity-based fiber sensors. The light intensity is first stabilized by inducing a sinusoidal intensity modulation and extracting the first-order sideband generated by self-phase modulation (SPM) in a nonlinear medium. The light with stabilized intensity is then sent through a sensor and the sensor induced power variation is magnified by first inducing a sinusoidal intensity modulation, then undergoing SPM, and finally extracting a higher-order sideband. The advantage of the proposed stabilization-magnification (SM) sensing scheme is experimentally demonstrated by applying a damped vibration on an intensity-based fiber sensor and comparing the minimum detectable strain value of the proposed scheme with that of a conventional sensing scheme. Experimental results demonstrate minimum detectable strain improvement by a factor of 3.93. This new SM sensing scheme allows for the detection of perturbations originally too weak to be detected by a given intensity-based fiber sensor, which will be beneficial for a variety of applications such as high frequency ultra-sound detection. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

The novel stabilization-magnification (SM) sensing scheme utilizes intensity modulation and self-phase modulation to enhance the sensitivity of fiber optic sensors to environmental perturbations. Experimental results demonstrate a 3.93-fold improvement in minimum detectable strain values.