HOMOGENOUS CONCEPT FOR THE COUPLING OF ACTIVE AND PASSIVE SINGLE-MODEDEVICES BY UTILIZING PLANAR GRADIENT-INDEX LENSES AND SILICON-V GROOVES

A new concept for a common interface between passive and active single -mode devices is proposed. The submicrometer alignment accuracy necess ary for efficient coupling of single-mode devices is extended to the r ange of some 10 mu m by beam expansion with planar gradient-index micr olenses; the increased angular sensitivity is satisfied by the use of planar surfaces. The imaging system is used off axis, resulting in a s uppression of backreflections in the range >60 dB. Of many possible va riations of components (fibers, waveguides, optoelectronic integrated circuits, edge-emitting lasers, vertical-cavity surface-emitting laser s, photodiodes), the coupling of fibers and waveguides is examined in detail. Expected coupling efficiency and sensitivity to lateral misali gnment are calculated by use of a modified beam-propagation method. In this way, the overall performance of the connector can be compared wi th existing connector concepts, and the feasibility of the concept is proven. Experimental results for the fiber-fiber connector are given. (C) 1997 Optical Society of America.