Wet-chemical fabrication of a single leakage-channel grating coupler

We demonstrate the fabrication of a unique optical device, the single leakage-channel grating coupler, using solgel techniques. Design specifications are outlined to establish the material criteria for the sol-gel compositions. Material choice and preparation are described. We evaluate the characteristics and performance of the single leakage-channel grating coupler by comparing the predicted and the measured branching ratios. The branching ratio of the solution-derived device is within 3% of the theoretically predicted value.