The System for Transparent Avionics Routing (STAR) is a high-speed multiple channel optical system currently under construction that interconnects electronic switches using multimode fibre ribbons. The requirements for the switch included (1) a very small footprint, (2) a form factor suitable for mounting as a board, (3) a cascadable circuit switch, (4) slow switching speed of microseconds of many high-speed channels and (5) electrical switching of optical signals (optical input and outputs). The philosophy behind the architecture of STAR is to not have any off-board high-speed signals. To implement STAR, a multichip module is formed consisting of the following chips: detector array, receiver array, high-speed electronic crossbar switch, and VCSEL array. These are bonded to an optoelectronic chip carrier that has on it optical waveguides which route light from an input fibre ribbon to the detectors and from the VCSELs to an output fibre ribbon. The waveguides have turning mirrors written on their ends to reflect the light out of the plane into the detectors or to reflect light from the VCSELs into guides. The guides mediate between the linear channel spacing of the fibres and the 2D array geometry of the VCSELs and receivers. (5 pages)