Fabrication and characterization of a dense optical bus attached to an AWG

Highly integrated photonic InP circuits raise the demand for an augmented number of optical ports. Therefore, we present the integration of an optical bus in our generic platform consisting of a compact Spot-Size Converter (SSC) array, and we demonstrate it by connecting it to an 8 x 8 AWG. The SSCs have a 25 µm pitch and expand the mode from 0.5 µm in the AWG waveguide layer to 3 µm after the SSC. The adiabatic conversion is based on a vertical taper with two linear sections. We measured 0.7 dB loss per fiber-chip coupling for a 700 µm long SSC device.