Modeling of Optical Interconnects

High Speed Diffraction Model

A novel numerical method to propagate optical fields in free space has been developed, the only approximation we made was that the vectorial nature of light was ignored. This approximation is quite valid since for most practical optical systems, the wavelength of light is small compared to apertures sizes in the optical system. Whereas traditional calculational methods often rely on Fresnel or Fraunhofer approximations.

Figure: Schematic of plane wave propagation.

Because the numerical method is based on the calculation of the Rayleigh-Sommerfeld integral using the FFT, it is fast and accurate. With the scheme, tilts and offsets can be readily treated. Specifically, tilted planes are treated by the remapping process, and offsets are handled by representing the plane wave components according to a shifted coordinate system with specific phase factors.

Monte Carlo Model

We have developed a Monte Carlo analysis for the optical performance of an optical interconnect system. Optical elements may include sources, detectors, free space components, and guided wave structures. These optical elements are characterized bt the mean values as well as tolerance distributions, for element positions, orientations, and design parameter. The primary output of the simulator is the optical efficiency of the optical system. From the optical efficiency one can readily calculate the distribution of optical efficiencies associated with a particular optical design by using Monte Carlo analysis. By specifying the value for acceptable efficiency, one can determine the manufacturing yield associated with that design.

Integrated Model

We have developed a modeling tool that integrates optical, cost, thermal, mechanical, and solder models under a common user interface. The models are connected together to allow trade-off studies between parameters existing within different models. We have applied the integrated models to a family of optical interconnect modules. As an example the figure below shows the trade off between system cost and detector area for an optical interconnect system.

Figure: A plot of cost as a function of detector area

Reference

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