Photo-Polymerized Acrylic Waveguides for Optical Interconnects
- PDF / 1,549,405 Bytes
- 6 Pages / 420.48 x 639 pts Page_size
- 11 Downloads / 179 Views
PHOTO-POLYMERIZED ACRYLIC WAVEGUIDES FOR OPTICAL INTERCONNECTS ROBERT R. KRCHNAVEK*, GAIL R. LALK**, AND ROBERT DENTON*** *Bellcore, Navesink Research and Engineering Center, Red Bank, NJ 07701 "**Bellcore, Morris Research and Engineering Center, Morristown, NJ 07960 ***2203 Sweetbriar Rd, Morrisville, PA 19067 ABSTRACT We have fabricated acrylic based optical channel waveguides using proximity photolithography as well as laser direct writing. The cladding layer is a photosensitive aliphatic urethane dimethacrylate and the guiding layer is a photosensitive aromatic acrylated epoxy. This material system provides good adhesion to a variety of substrate materials. Since both the guiding and cladding layers are applied, these materials can be employed in several electrical/optical applications including multi-chip modules using Si, Si0 2 , and polyimide as well as high speed electronic board technologies using teflon based substrates. Loss measurements show a guide loss of less than 0.08 dB/cm for multi-mode waveguides fabricated using the direct write laser technique. Lithographically defined guides have a loss of 0.3 dB/cm for similar size waveguides. INTRODUCTION As the speed of integrated circuits (ICs) continues to increase, the ability to fully utilize the benefits of this increased speed in systems places an increasing burden on the ability to interconnect various ICs at the board level. Although electrical interconnects have not exhausted their capabilities, signal delay over the long distances associated with today's system boards can limit overall performance, especially in the area of system clock distribution. Optical interconnects offer the potential to solve many signal distribution problems. Fiber optics have seen widespread use in long-haul data transmission in the telecommunications industry. There use in short distance data communications has been limited to board-to-board interconnections on the order of meters. There use at the board level, where typical distances are of the order of cms has been limited because of the difficulty in fabricating boards using fibers. In addition to the difficulty in laying the fiber down onto the board, several problems arise when forming sharp bends, interfacing with devices (lasers and detectors), and fabricating fiber devices (couplers, splitters, interferometers, etc). These difficulties have stirred an interest in optical waveguides as a means of benefitting from the high speed signal distribution that optics offers while at the same time using a technology that is compatible with multi-chip module and hybrid technology. Optical waveguides at the board level can be fabricated by a variety of methods using a variety of materials. 2 5 In particular, if the board is silicon as in many multi-chip modules, waveguides are easily fabricated using doped silicon dioxide. Waveguides have also been demonstrated using a variety of organic compounds, including polyimide and poly-methyl methacralate. However, most schemes produce waveguides with a significant amount of loss -
Data Loading...
