Abstract: An optical coupling system having a high efficiency in coupling light from a light source to an optical fiber. The system may have a ball lens and an aspherical lens situated along the same optical path. The ball lens may be glass and the aspherical lens may be plastic. The ball lens may have optical aberrations common to spherical lenses. The aspherical lens may compensate for such aberrations. The glass ball lens may carry more power and have better thermal properties than the plastic lens, and thus compensate for latter's possibly weaker thermal properties. Together, the system may have sufficient power, low distortion, good thermal characteristics and high coupling efficiency.

Abstract: A coupler for coupling light between an optoelectronic element and an optical fiber. The coupler has a fiber stop that is made of a material that has an index of refraction that effectively matches the index of refraction of the optical fiber being coupled to the optoelectronic element. The fiber stop may be flat or rounded. It may be a discrete or molded part of the coupler assembly. The end of the fiber being stopped may be flat or rounded.