A selfoc lens is a converging lens that bundles the diverging light rays of an optical fiber for a detector. In a conventional lens, the light undergoes refraction at the transition between air and glass, which changes the direction of the light rays hitting the glass surface. The situation is different with the Selfoc lens, where the refractive index
in the lens is different. In the selfloc lens, the incident light is uniformly and continuously deflected toward the focal point by gradual density changes corresponding to that of the gradient index.
The selfoc lens has a much simpler structure than a conventional microlens
and can have a required refractive index by controlled density changes. The changes in refractive index are achieved by a high temperature process in which ions diffuse into the material.O/E converter
and concentrate the light rays onto the optical detector. The designation Selfoc lens is a trademark of the Nippon Sheet Glass Company.