Experimental Validation and Uncertainty Quantification of a Single-Mode Optical Fiber Transmission Model

The radial intensity distribution of a transmission from a single-mode optical fiber is often approximated using Gaussian-shaped spatial field distributions. While such approximations are useful for some applications, they do not accurately describe optical transmission intensity off of the axis of propagation. A recent paper was presented that more accurately describes the intensity distribution, and this paper presents a simple experimental setup that verifies the model's accuracy through formal uncertainty quantification procedures. Agreement between the model and the experiment is established both on and off of the axis of propagation. These results are then discussed in the context of displacement sensor designs based on the optical lever architecture. Transmission behavior off of the axis of propagation controls the sensor performance when large lateral offsets (25-1500 μ m) exist between transmitting and receiving fibers. The practical implications of modeling accuracy over this lateral offset region are discussed as they relate to the development of high-performance, intensity-modulated optical displacement sensors. Specifically, the sensitivity, linearity, resolution, and displacement range of a sensor are functions of the relative positioning of the sensor's transmitting and receiving fibers. It is concluded that the predictive capability of the model presented in this paper could enable an improved methodology for high-performance sensor design.