Optical Computing with Micro-Fluidic Actuator Switch Technology (uFAST) for Parallel Processor Crossbar Switching

Optics hold great potential for the implementation of interconnection networks for large-scale parallel computers. A common the goal is to have a reconfigureable crossbar network where each processor can be connected to any other processor or memorydynamically. Central to this topology is a binary optical switch. Advances in optical switching in the telecommunications industry hold some promise based on the non-blocking switch fabrics that are compatible with the crossbar network goals. One majorissue has been the high power consumption and slow switch speeds associated with the technologies used in telecommunications optical switches. Switch speeds are in the milliseconds range and each state change consumes mJ's. Some optical computingarchitectures propose communications between processors by transitioning from a polymer waveguide to a free-space switch to enable inter-processor communications. Significant signal losses result from this approach. Aret¿'s Micro-Fluidic Actuator SwitchTechnology (uFAST) overcomes the loss issues and provides orders of magnitude faster switching speed and orders of magnitude lower energy consumption than commercially available telecommunications switches. This waveguide based switch fabric eliminates theneed to transition into free space and is compatible with being built directly in to the processor chip.Optical Switches are one of the major elements in the burgeoning multibillion dollar telecommunications industry. The uFAST and provide potentiallysignificant benefits from a performance perspective for optical computing due to the anticipated switch rates of < 1us. It also hods significant advantages when compared to other switch technologies currently being pursued. In general optical switches fallinto either the free space, MEMS being the only technology in this field, or substrate waveguide categories including liquid crystal, thermo Optic and Bubble technology.mFAST's primary advantages over all of these approaches are switch speed, power, consumed energy and operational voltage. Switch speeds are 3 to 4 orders of magnitude faster than any of these technologies. Power consumption is 2 to 3 orders of magnitudelower and the resulting consumed energy consumed is 6 to 8 orders of magnitude less. Given the energy is conservatively stored in capacitive actuator, the option of retrieving this energy also exists. This is not possible with the Bubbles, Thermo-optic orLiquid crystal approach.Operation at low voltage provides two additional advantages. First the ability to retrieve energy from the actuator and generate lower voltage will result in more efficient power supplies. The second advantage is that with such low voltage requirements,the ability to fabricate the power supply electronics as part of the silicon waveguide exists.