Through-wafer optical interconnection coupling characteristics

Both the optical coupling and resulting optical crosstalk characteristics for LED-based through-wafer optical interconnections have been measured within a simulated stacked wafer environment. Using integrated SiO₂ Fresnel phase plate lens arrays, a nearly 4:1 improvement in received signal was noted over the configuration without lenses. Interchannel crosstalk measurements indicate that from an optical standpoint, high interconnect densities (250 μm pitch) are obtainable with reasonable noise margins over a range of distances of interest for stacked wafer architectures