Optical fibers are widely used in different applications, and they play an important role in long-distance optical communication. In practice, launching light into optical fibers, especially to single-mode ones, can be a challenging task and the fiber coupling lens must be carefully chosen. In this example, we select two commercially available lenses, with the same effective focal length, but different surface types. They are evaluated, for the task of coupling light into a single-mode fiber, in terms of coupling efficiency which is calculated by using the overlap integral.
