SPLICE LOSS IN SINGLE-CORE AND TWIN-CORE BURIED-CHANNEL WAVE-GUIDE DEVICES

We quantify the magnitude of the power loss incurred when a square-cor e buried channel waveguide (BCW) is spliced to a standard circular-cor e telecommunications fibre. With a view to minimizing the dissipated p ower, we show that a simple equal-core-area criterion provides an eleg ant means of determining the optimum core dimensions. This result is f ound to hold for more general BCW cross-sections that possess a reason able degree of symmetry. The fundamental problems of waveguide misalig nment and angular tilt are also investigated and their effect on splic e loss is quantified. Our theoretical model is applied to both single- and twin-core waveguides.