Tolerancing of board-level-free-space optical interconnects

Area of Science:

• Optoelectronics and Photonics
• Optical Engineering
• Computer-Aided Design

Background:

• Optical interconnects require integration with electronic packaging for maturity.
• Free-space optical interconnects face challenges in alignment and heat dissipation.
• Assembly and manufacturing variations impact alignment tolerancing over long distances.

Purpose of the Study:

• To develop a computer-aided analysis for determining active and passive element tolerances in free-space optical interconnects.
• To establish a procedure for optimizing system-level specifications like yield and cost.
• To analyze the impact of various tolerances on optical throughput and system performance.

Main Methods:

• Utilizing optical design software (e.g., Code V) to model system design.
• Performing Gaussian or Fresnel propagation to calculate optical throughput.
• Employing sensitivity analysis and Monte Carlo techniques for tolerancing analysis.
• Applying parametric sampling for yield or cost optimization.

Main Results:

• A computer-aided analysis procedure was demonstrated for active and passive element tolerancing.
• Sensitivity analysis identified the relative effects of perturbations on optical throughput.
• Monte Carlo simulations assessed system yield and cost.
• A design example showed most tolerances are achievable with current technology.

Conclusions:

• The developed computer-aided analysis effectively determines tolerances for free-space optical interconnects.
• The methodology allows for optimization of system yield and cost.
• Current manufacturing technology can meet the alignment tolerance requirements for board-level optical interconnects.