A CMOS VLSI pilot and support chip for a liquid crystal on silicon 8 × 8 optical cross-connect

As the telecommunication world turns to wavelength division multiplexed optical transport networks (WDM) needs are growing for large-scale optical cross connects (OXC). Electrically addressed nematic liquid crystal gratings (LC) using Liquid Crystal On Silicon technologies (LCOS) take advantage of VLSI driving capabilities and can be an interesting solution. We present a mixed analogue and digital CMOS chip for an LCOS OXC with 8×8 fibre capacity. LC command is analogue. Parameters and electrode voltages are programmed through an IEEE-EPP interface. An optical 1.5µm wavelength set-up has shown to produce deviation with up to 80% efficiency.