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As fiber optics becomes a standard means of transmitting long haul telecommunication signals. costs of adopting fiber solutions for various other communication applications steadily decrease. Optics starts to challenge copper-based solutions in many short-distance data communication domains. Recent progress in developing vertical -cavity surlaceemitting lasers (VCSEL) has lead to a belief that a proper combination of the VCSEL and fibers can provide a cost-effective solution to many bandwidth-demanding local data communication bottleneck problems. A trend to develop VCSEL-hased fiber optic parallel data links has been witnessed [1-2]. Among the most notable approaches are the parallel fiber link prolect by the Opto-electronic Technology Consortium (OETC) [1]. the Optobus project by the Motorola Corp [21. These, along with many other similar, approaches feature 1D array of bit-parallel connections of optical data between a ID VCSEL array and a ID photodetector array. A lD fiber ribbon containing various fiber channels is used as flexible parallel data channels. As demand for bandwidth rapidly increases, wider and wider 1D ribbons containing more and more parallel channels are being proposed. To cope with future bandwidth demand, a direct extension of the 1D approach to a 2D form has also been studied. 2D VCSEL arrays are under development. Methods of fabricating small 2D arrays of individual fibers are being explored [341. It was noted that unless active alignment methods are successfully developed, it is difficult to control core pitch fluctuations of such a fiber array. A somewhat different 2D approach was recent proposed [5]. It uses a fiber image guide (FIG) which contains a large number of closely packed fibers to transmit the image of the VCSEL to the other side. A FIG simply images between a 2D input and output arrays. Among mentioned advantages of this approach are its capability to transmit a scalpel number of parallel channels and its relaxed alignment condition. In this talk, we quantitatively study various interface problems this FIG-based approach may experience and try to understand its capabilities and limitations.
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