Optical circuits based on low-loss glass waveguide on silicon are a practical and promising approach to integrate different functional components. Fiber attachment to planar waveguide provides a practical application for optical communications. Microwave Plasma Assisted Chemical Vapor Deposition (MPACVD) produces superior quality, low birefringence, low-loss, planar waveguides for integrated optical devices. Microwave plasma initiates the chemical vapor of SiCl4, GeCl4 and oxygen. A Ge-doped silica layer is thus deposited with a compatible high growth rate (i.e. 0.4 - 0.5 micrometer/min). Film properties are based on various parameters, such as chemical flow rates, chamber pressure and temperature, power level and injector design. The resultant refractive index can be varied between 1.46 (i.e. pure silica) and 1.60 (i.e. pure germania). Waveguides can be fabricated with any desired refractive index profile. Standard photolithography defines the waveguide pattern on a mask layer. The core layer is removed by plasma dry etch which has been investigated by both reactive ion etch (RIE) and inductively coupled plasma (ICP) etch. Etch rates of 3000 - 4000 angstrom/min have been achieved using ICP compared to typical etch rates of 200 - 300 angstrom/min using conventional RIE. Planar waveguides offer good mode matching to optical fiber. A polished fiber end can be glued to the end facet of waveguide with a very low optical coupling loss. In addition, anisotropic etching of silicon V- grooves provides a passive alignment capability. Epoxy and solder were used to fix the fiber within the guiding groove. Several designs of waveguide-fiber attachment will be discussed.

Data link components are demonstrated based on 850 nm vertical cavity lasers (VCSELs) and short wavelength GaAs PIN detectors. These components are the foundation of an array data link solution set and offer easy incorporation with traditional multimode fiber based backplanes, or polymer waveguide based backplanes

This paper describes the technical approach and progresses of the POINT program. This project is a collaborative effort among GE, Honeywell, AMP, AlliedSignal, Columbia University and University of California at San Diego, sponsored by DARPA/ETO to develop affordable optoelectronic packaging and interconnect technologies for board and backplane applications. In this paper, we report the development of a backplane interconnect structure using polymer waveguides to an interconnect length of 280 mm to demonstrate high density and high speed interconnect, and the related technical development efforts on: (a) a high density and high speed VCSEL array packaging technology that employs planar fabrication and batch processing for low-cost manufacturing, (b) passive alignment techniques for reducing recurrent cost in optoelectronic assembly, (c) low-cost optical polymers for board and backplane level interconnects, and (d) CAD tools for modeling multimode guided wave systems and assisting optoelectronic packaging mechanical design.

Due to the explosive growth in high speed network communication and the rapid advance in the processor speed and processing power, data transfer bandwidths between chips, modules, board, backplane and cabinets have increased drastically. The required interconnect bandwidths for efficient data communication across different platforms have increased accordingly. The optical backplane offers a much higher data bandwidth and interconnect density with minimum cross-talk. However, in order to successfully deploy optical interconnect in complex electronic systems such as board and backplane and offer performance/cost comparable of superior to electronic solutions, the development of optoelectronic interconnect devices, components, packaging and processing technologies must be compatible with the existing electronic interconnect counterparts. In this work, we report the recent development of high density optical interconnect technology using VCSEL and polymer waveguides for board and backplane level applications

This paper describes the technical approach and progresses of the POINT (Polymer Optical Interconnect Technology) program. This project is a collaborative effort among GE, Honeywell, AMP, AlliedSignal, Columbia University and University of California at San Diego (UCSD), sponsored by DARPA/ETO to develop affordable optoelectronic packaging and interconnect technologies for board and backplane applications. In this paper, we describe the recent development under this program in the following areas: (a) a high density optical interconnect for board and backplane applications using polymer waveguides (Polyguide) to demonstrate high I/O density (100 /spl mu/m channel spacing) and high speed (/spl sim/1 Gbps) interconnect with an interconnect distance to 280 mm, (b) a high density and high speed VCSEL array packaging technology that employs planar and batch fabrication processes scaleable to large volume, low-cost manufacturing, (c) passive alignment techniques for reducing the recurrent cost in an optoelectronic assembly, (d) low-loss optical polymers for board and backplane level interconnects, and (e) CAD tools for modeling multimode guided wave systems and assisting optoelectronic packaging mechanical design.

The development of multimode passive polymer optical waveguide components for board and backplane interconnect applications, such as in the the DARPA-sponsored, ''Polymer Optical Interconnect Technology (POINT)'' program,(1,2) require several optics design issues to be addressed including efficiency and modal noise. For example, the mating of arrays of sources, detectors, and fibers requires appropriate fanout structures to match the component pitch. Here we consider designs for such structures employing multimode polymer waveguides, including both abrubt and smooth bending elements. We investigate these structures using a new multimode BPM simulation CAD tool, and consider the bend losses as a function of geometry, angle, and source condition. The results are compared with experimental observations on devices fabricated for use in the POINT demonstration module. The simulation closely matches the experiment, demonstrating the utility of such efforts in practical component development.

The Polymer Optical interconnect Technology (POINT) is a collaborative program among GE, Honeywell, AMP, AlliedSignal, Columbia University and University of California at San Diego (UCSD), sponsored by ARPA, in developing affordable optoelectronic packaging and interconnect technologies for board- and backplane-level optical interconnect applications. The POINT program leverages on the existing electronic design, processing, fabrication and MCM packaging technologies to optoelectronic packaging. The POINT program also incorporates several state-of-the-art optoelectronic technologies that include: high speed VCSEL for multi-channel data transmission; flexible optical polymer waveguides and low-loss polymers for board and backplane interconnects; low-cost diffractive optical elements (DOE) for board-to-backplane interconnect; and use of molded MT-type connectors to reduce weight and size. In addition, to further reduce design and fabrication cycle times, CAD tools for multimode optical waveguide modelling, and for mechanical modelling of optoelectronic packaging will be employed to aid the technology development.

The design and fabrication of a low cost laser diode to fiber optic coupler is discussed. A single diffractive optical element was used to provide uniform coupling efficiency over a 40 nm bandwidth. The element was optimized to maintain constant coupling efficiency with small tilts and decenters. An iterative method referred to as radially symmetric iterative discrete on-axis (RSIDO) encoding was used to determine optimum fringe placement and profile.