Fully embedded board level optical interconnects: from point-to-point interconnection to optical bus architecture

Abstract

This paper presents the latest progress toward fully embedded board level optical interconnects in the aspect of optical bus architecture design, waveguide fabrication and device integration. A bidirectional optical bus architecture is designed and can be fabricated by a one-step pattern transfer method, which can form a large cross section multimode waveguide array with 45° micro-mirrors by silicon hard molding method. The waveguide propagation loss is reduced to 0.09dB/cm and the coupling efficiency of the metal-coated reflecting mirror is experimentally measured to be 85%. The active optoelectronic devices, vertical surface emitter lasers and p-i-n photodiodes, are integrated with the mirror-ended waveguide array, and successfully demonstrate a 10 Gbps signal transmission over the embeddable optical layer.