Optical star coupler

Claim 1

A star coupler comprising: a first group of optical waveguides having tapered portions, each tapered portion terminating in an end face of the waveguide, said tapered portions being arranged adjacent to one another so that the end faces of the waveguides form a first group end face having a periphery; a second group of optical waveguides having tapered portions, each tapered portion terminating in an end face of the waveguide, said tapered portions being arranged adjacent one another so that the end face of the waveguides form a second group end face having a periphery; and a graded index rod lens having first and second opposite end faces having peripheries; characterized in that: the first group end face is connected to the first end face of the graded index rod lens; the second group end face is connected to the second end face of the graded index rod lens; and the entire periphery of the first end face of the graded index rod lens surrounds and is spaced from the entire periphery of the first group end face, and the entire periphery of the second end face of the graded index rod lens surrounds and is spaced from the entire periphery of the second group end face, such that radiation emerging from the tapered portions of the first group of waveguides will be incident on the first end face of the graded index rod lens and will be focused by the graded index rod lens onto the tapered portions of the second group of waveguides.