Lensed optical fiber having high coupling efficiency, process of production and apparatus for production of same, and laser diode module

1. Field of the Invention A lensed optical fiber comprised of an optical fiber having a core and a cladding and a lens portion formed at its front end, a process of production of a lensed optical fiber, an apparatus for its production, and a laser diode module. The lens portion of the lensed optical fiber is comprised of a substantially flat portion formed at an end face of the core, slanting faces formed at an end face of the cladding, and convex curved faces including part of the core between the substantially flat portion and slanting faces.