Design And Realization Of Waveguide-based Chip-to-chip Optical Interconnection Network

Recently, with the development of information technoledge, such as telecommunications and computers, computers'processing speed was required to hundreds of billions per second or even trillions times per second, especially in high-speed information networks. But the performance of conventional electrical interconnection technology, because of the inherent physical restrictions, has become more and more unsuitable for high-speed information processing and transmission requirements. As a result, domestic and foreign researchers pay more attantion to optical interconnection technology aiming to replace the traditional copper wire interconnects, with photons rather than electronic as a medium, to realize high-density, high-speed communtions between chips.This paper focuses on waveguide-based interchip optical interconnection network. Firstly, from the Maxwell equation, the step-index planar waveguide were analyzed to get its wave equation, field distribution and related parameters. As the equation could not be solved exactly, we introduced finite difference beam propagation method (FDBPM) and derived it in detail for light transmitting in waveguides. And with it, we realized the design and simulation of optical waveguide devices in Matlab.Then, we proposed a new chip-to-chip optical interconnect structure on PCB, including VCSEL laser, waveguide coupler, embedded optical waveguide and optical receivers. The optical interconnect layer is the key to its implementation. So we designed and analyzed the optical interconnect layer in FDBPM, and the simulation of rectangular multi-mode waveguide in Matlab shows that the transmission efficiency would be greater than 99%. Next, the production process of waveguide was discussed, and through experiments, we summed up a new waveguide fabrication process named doctor bladding, that mainly includes two steps:mold-making and waveguide-making. The whole fabrication process was simple and easy to control for the size of waveguide core, suitable for making large-size waveguides and other prominent advantages. Then, the samples of waveguide fabricated were tested and results showed the average waveguide loss was about 3dB, that would be enough to meet the communication requirements.Finally, according to the characteristics of the interchip interconnection network, we designed three different network models:fully-connected network based of bending waveguide, all-optical switch interconnection network based of optical switch array and mesh-based opto-electronic hybrid connected network. By analyzing their own characteristics, the third option was chosen. We successfully fabricated a 2x2 Mesh-based optical interconnection network for demonstrations, which included parallel optical transmitter /receiver module-VCSEL/PIN array, and realized the optical signal transmitting in waveguides embedded in PCB. Experiments confirmed that each node of this network could realized to move up, down, left, right, the light's wavelength was 850nm, the data rate in each channel could reach above 3.125 Gbps and the bit error rate (BER) could be up to 10-16, which would be enough to satisfy communications.In a word, a new interchip waveguide-based optical interconnection network, with a conventional optical interconnection layer in printed circuit boards, was designed and realized, which could overcome the bottleneck of high-speed electrical interconnecs. It would be a innovation and could have important practical significances and applications to the development of broadband, high-speed, large-capacity information communication networks and parallel processing and transmission of high-performance computer systems.