Inclination sensing based on a fiber-ring laser and a fiber-Bragg grating with a precise resolution

We design an inclination-sensing system based on a fiber-ring laser integrated fiber-Bragg grating (FBG) whose peak wavelength is changed by the axial strain. By replacing a conventional broadband light source with the fiber-ring laser, we raise the sensing power to 3.1 dBm, the peak-to-noise ratio to 65.31 dB, and reduce the 3-dB bandwidth to 0.06 nm. Thus, the sensitivity and resolution of the proposed system are greatly improved. By using an FBG integrated with a pendulum ball used as a sensor head, the resolution of the angular inclination could reach 0.015 nm per degree. These specifications are qualified for the general practice of the pendulum-sensing system.