The use of miniaturized optical components for chip level communications is increasing rapidly. The possible applications include: optical switching, signal monitoring, I/O reconfiguration, and add/drop multiplexing. Micro-Opto-Electro-Mechanical Systems (MOEMS) based on customized IC fabrication processes are being used to assemble system-level architecture for integration into mainstream circuitry. MOEMS devices based on dynamic diffractive elements are currently investigated for both their signal routing capabilities and de-multiplexing properties. These characteristics are expected to increase the speed of optical data transfer. This paper focuses on the current status of the MOEMS research program for Free Space Optical inter-chip communication at the College of Nanoscale Science and Engineering, University at Albany- SUNY (CNSE) based on the MEMS Compound Grating (MCG) design. Operational characteristics of these MCG devices have been shown to operate at high voltages (>15V) compared to 5V levels prevalent in conventional integrated circuits. The specific goal of this work is to improve performance while minimizing power consumption. A design change that incorporates a higher capacitance and a lighter suspension system has been studied. A new fabrication process has been constructed utilizing Polyimide as a structural material. Fabrication steps have been optimized for best MCG device performance. Experimental results from both research tasks will be presented.
The eventual widespread insertion of microoptoelectromechanical systems (MOEMS) into the marketplace rests fundamentally on the ability to produce viable components that maximize optical performance while minimizing power consumption and size. Active control of surface topology allows for one component to perform multiple functions, thus reducing cost and complexity. Based on the patented MEMS compound grating (MCG), extension of the research at the College of Nanoscale Science and Engineering (CNSE) at the University of Albany, New York, to novel designs, materials, and fabrication methods yielded low-power, high-performance prototypes. The main focus of this work is on the development of a polymer version (including a sacrificial layer, in some designs) of the MCG, which allows for ease of fabrication and a reduced electrostatic actuation voltage. Following a system design effort, several generations of the component are fabricated to optimize the process flow. Component metrology, electromechanical characterization, and initial results of optical tests are reported. A second example presented is the design and prototype fabrication of a spring micrograting using a customized SOI process. This highly flexible component builds on the MCG concept and yields an order of magnitude reduction in actuation voltage.
Micro-Opto-Electro-Mechanical Systems (MOEMS) have found a variety of applications in fields such as telecommunications, spectroscopy and display technology. MOEMS-based optical switching is currently under investigation for the increased flexibility that such devices provide for reconfiguration of the I/O network for inter-chip communication applications. This potential not only adds an additional degree of freedom for adjustment of transmitter/receiver links but also allows for fine alignment of individual channels in the network link. Further, this use of diffractive arrays for specific applications combines beam steering/adjustment capabilities with the inherent wavelength dependence of the diffractive approach for channel separation and de-multiplexing. Research and development has been concentrated on the progression from single MOEMS components to parallel arrays integrated with optical source arrays for a successful feasibility demonstration. Successful development of such an approach will have a major impact of the next generation communication protocols.
This paper will focus on the current status of the MOEMS research program for Free Space Optical inter-chip communication at the College of NanoScale Science and Engineering, University at Albany-SUNY (CNSE). New versions of diffractive arrays stemming from the basic MEMS Compound Grating (MCG; patent #5,999,319) have been produced through various fabrication methods including the MUMPs process1. Most MEMS components relying on electrostatic actuation tend to require high actuation voltages (>20V) compared to the typical 5V levels prevalent in conventional integrated circuits. The specific goal is to yield improved performance while minimizing the power consumption of the components. Structural modifications through the variation in the ruling/electrode spacing distance and array wiring layout through individually addressable gratings have been studied to understand effects on the actuation voltage and cross talk, respectively. A detailed overview of the optical and mechanical properties will be included. Modeling results along with the mechanical and optical testing results have been detailed and compared with previously obtained results. Future work focuses on alternate material sets for a reduction in operational voltage, improvements in optical efficiency and technology demonstrators for verification of massively parallel I/O performance.