Design of Micro Lens Arrays Coupling with Fiber Arrays and Analysis of the Coupling Loss

To couple parallel lights into an array of 16 singlemode fibers and an array of 16 multimode fibers,two types of circular micro lens arrays with different crown heights are proposed.Each array is composed of 16 lined-up plano-convex micro lenses with the diameter of 120 μm,and the space of two adjacent lenses is 127 μm.The imaging properties of the micro lenses are simulated and it is shown that parallel lights are converged after passing through the micro lenses,and the diameters of the spots at the image planes of the two kinds of micro lens are 8.0 μm and 32.5 μm.The coupling losses when there are lateral,longitudinal and angular deviations between the micro lens array and the fiber array are also analyzed,and the factor that influences the coupling loss most is found to be angular deviation.It is concluded that angular deviation must be avoided when the micro lens array and fiber array are collimated.