Trade-offs between lens complexity and real estate utilization in a free-space multichip global interconnection...

Area of Science:

• Optics and Photonics
• Integrated Optics
• Optical Interconnects

Background:

• Terabit networks require high-density optical interconnects.
• Free-space optics offer a potential solution for high-bandwidth data transfer.
• Current systems face challenges in achieving optimal lens design and chip real estate utilization.

Purpose of the Study:

• To evaluate the efficiency gains from using aspherical lens surfaces in free-space optical interconnects.
• To analyze the trade-offs between lens complexity and chip area density.
• To determine an optimal numerical aperture for vertical cavity surface emitting lasers (VCSELs) to maximize area density.

Main Methods:

• Conceptualizing the FAST-Net (Free-space Accelerator for Switching Terabit Networks) architecture.
• Employing wide-field-of-view imaging lenses for shuffle interconnect patterns.
• Replacing spherical lens surfaces with aspherical surfaces to simplify optics.
• Analyzing the disparity between narrow VCSEL beams and wide field-of-view optics.
• Conducting trade-off analysis between lens complexity and chip real estate.

Main Results:

• Aspherical surfaces offer efficiency gains by accommodating narrow VCSEL beams within wide field-of-view optics.
• An optimal numerical aperture for VCSELs was identified that maximizes area density.
• The study provides a framework for designing high-density free-space interconnection systems.

Conclusions:

• Aspherical optics are crucial for simplifying free-space interconnects and enhancing efficiency.
• Optimizing VCSEL numerical aperture is key to maximizing chip area density in optical systems.
• The FAST-Net concept and design framework facilitate the development of advanced terabit networks.