Optical sensor having π-phase shifted Bragg grating and optical sensing system using same

An optical sensing system comprising:

• an optical sensor
• a frame having a deformable member mounted to the frame, and
• a sensing optical fiber being fixedly attached to a portion of the deformable member, the sensing optical fiber having at least one πphase-shifted fiber Bragg grating inscribed thereon, the at least one πphase-shifted fiber Bragg grating being birefringence-free and having a filter function exhibiting a single resonance peak, the at least one πphase-shifted fiber Bragg grating of the sensing optical fiber deforming together with the deformable member when the frame is subjected to a force;
• and
• a signal conditioner optically coupled to the sensing optical fiber, the signal conditioner being adapted and configured to measure a Bragg wavelength shift ΔλB of the πphase-shifted fiber Bragg grating and to generate a signal representative of the Bragg wavelength shift ΔλB;
• and
• a computer communicatively coupled to the signal conditioner and being configured to sense a measurand of interest based on the Bragg wavelength shift ΔλB and on known properties of the optical sensor.