Alignment tolerance study between VCSEL arrays and a new kind of ordered fiber array technology considered for two-dimensional parallel optical interconnects

There is a need for two dimensional parallel optical interconnects for large bandwidth transfer of data over a distance ranging from tens of centimeters to a few meters. Optical transmission of data through "free-space" using imaging or diffractive elements would fulfil this need for very large bandwidth and high throughput density, but is not yet a practical approach. A commercially viable approach in the shorter term is to use optical fiber technologies as the communication medium. Fiber image-guides can be mass produced and are easy to align with the source but have insertion losses of the order of -3 dB. Ordered fiber arrays can be constructed using the same technology as fiber image-guides, and can have lower insertion losses but at the cost of reduced alignment tolerances.;We present a model for the numerical calculation of the insertion loss in ordered fiber arrays when coupling light from an array of VCSELs of equal dimensions. We then apply this model to study the impact of alignment on insertion losses as a function of the different fiber array parameters: core radius and of the individual fiber elements, and the dimensions of the array. We conclude that the alignment tolerances for multimode ordered fiber arrays should be compatible with present-day connector technology.