Fiber optic interferometric sensors of stress and acoustic pressure on twin-core waveguides

Stress and acoustic pressure sensors in twin-core waveguides have been studied experimentally. By means of the phase shift of interference fringers realized in twin-core waveguides the sensitivities of stress and pressure sensors which are correspondingly $3~rad \cdot m\cdot H^{-1}$ and $6~rad\cdot m^{-1}\mu m^{-1}$ and their temperature properties have been defined. Some advantages of the twin-core sensor over the interferometric single-core sensors have been cleared up.