Numerical study on the propagation property of a single mode fiber beam combiner

• We give detailed discussions on the power transmission of optical field.
• We discuss the effects of taper and output fiber on the performance of the combiner.
• The core NA of the output fiber has a negligible effect on the transmission efficiency.
• The taper length should be large enough to get high transfer efficiency.
• The taper ratio and the core diameter of output fiber should be optimized.

We numerically investigate the propagation property of a 3×1 single mode fiber beam combiner in this paper. The evolvement of the optical field in the combiner is studied and the effects of the parameters such as the taper length, the taper ratio, the core diameter and numerical aperture of the output fiber on the performance of the combiner are analyzed. We find that the numerical aperture of the output fiber only has a negligible effect on the transfer efficiency of the combiner, while the taper length should be large enough to realize high efficiency. It is also suggested that the taper ratio and the core diameter of output fiber should be optimized for improving the performance of the combiner.