MOEMS arrays for interconnect applications

The evolution of computer chip technology has been marked by a steady progression toward higher performance which will soon be Limited by the time delay associated with interconnects. This has led to consideration of alternate interconnect methods to complement or replace conventional metal/dielectric architectures for both intra-chip and chip to chip communications. Among the proposed alternatives is an optical approach using new, massively parallel arrays of emitters and detectors. The interconnect medium for this approach, however, is still under conceptual design and has spawned many candidates. Various configurations of static micro-optic arrays have been developed however, recent consideration has been given to active, reconfigurable optics based on micro-electro-mechanical systems (MEMS) technologies. These Optical-MEMS or MOEMS have enabled innovative devices which can control phase, amplitude and direction of input light beams. One area which has recently received much attention is the creation and use of both reflective and diffractive arrays. This paper will present the development and use of active, reconfigurable MOEMS prototypes applied to proof of principle optical interconnect systems. We have been studying several array architectures consisting of gratings, columnar reflectors and micromirrors. For example, the patented MEMS-based Compound Grating (MCG)(1) is currently being developed to enable a new class of diffractive arrays which can be used as a massively parallel switch. The MCG is a device which is a superposition of two or more diffraction gratings whose surface topology can be controlled. Various prototype arrays of these MCG devices have been designed, modeled, fabricated and tested. Initial results of these studies will be presented. In addition, application of the Digital Micromirror Device (DMD(TM), Texas Instruments, Inc.) to this problem will also be discussed Using a custom control software and optical setup, preliminary results from the integration of a DMD into an optical interconnect test stand will be presented.