An intensity function for inclined multimode optical fiber sensors

The performance of a two-optical-fiber intensity-modulated sensor depends on the geometrical parameters of the sensors. A significant improvement in the performance is expected if the transmitting and receiving sfibers are configured in inclined feature instead of being configured in parallel feature. The linear operating range and sensor sensitivity depend on the angle between transmitting and receiving fibers, core and fiber radius, and inter-fiber spacing. Moreover, the intensity function plays an important role in designing multimode optical fiber sensor, especially, in designing two-optical-fiber intensity-modulated sensor. As being a design parameter of the sensor, it is essential in determining the sensor sensitivity due to the reflected power changes. The mathematical model of the intensity function applicable to inclined geometrical configurations is developed and simulated responses are studied. Experimental validation of the mathematical model is performed using carefully designed experiments. The simulated responses and the experiment results are compared with the responses of another mathematical model which was developed by Gang He.