The WA Centre of Excellence for Microphotonic Systems (COMPS) is carrying out research into and development of Opto-VLSI technology for manipulation of material showing electro-optic effects. This includes the design and fabrication of Opto-VLSI chips featuring low loss, low polarisation sensitivity, and low switching voltage at near-infrared wavelengths.
An Opto-VLSI processor comprises an array of liquid crystal cells driven by a very-large-scale-integrated (VLSI) circuit that generates digital holographic diffraction gratings to steer and/or shape optical beams.
Fabricated Opto-VLSI processors are electronically controlled, software configure, polarisation independent and cost effective because of the high volume manufacturing capability of VLSI chips. Opto-VLSI processors have the capability to control multiple fibre ports in one compact Opto-VLSI module, and are very reliable as beam steering/multicasting is achieved with no mechanically moving part.
Each pixel is assigned a few memory elements that store a digital value, and a multiplexer that selects one of the input voltages and applies it to the aluminium mirror plate. Opto-VLSI processors are electronically controlled, software-configured and polarisation independent. They are cost effective, because of the high volume manufacturing capability of VLSI chips; have the capability of controlling multiple fibre ports in one compact Opto-VLSI module; and are very reliable since beam steering is achieved with no mechanically moving parts.
Indium-tin oxide (ITO) is used as the transparent electrode, and evaporated aluminium is used as the reflective electrode. The ITO layer is generally grounded and a voltage is applied at the reflective electrode by the VLSI circuit below the liquid crystal layer.
The application areas of Opto-VLSI are numerous, including:
Opto-VLSI beam steering
By configuring the Opto-VLSI processor, beam steering can be accomplished. Phase holograms can be uploaded onto the Opto-VLSI processor so that light beams can be steered to a specific direction without involving any moving parts.
By configuring the Opto-VLSI the light beam can be dynamically split into multiple directions. This has wide applications in optical communications. Optical communication networks are currently limited by reconfigurability, to add or drop users or changes in service. This new technology can increase the flexibility and versatility of a network.