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A practical optical link system was prepared with a transmitter (Tx) and receiver (Rx) for reducing EMI
(electromagnetic interference). The optical TRx module consisted of a metal optical bench, a module printed circuit
board (PCB), a driver/receiver IC, a VCSEL/PD array, and an optical link block composed of plastic optical fiber (POF).
For the optical interconnection between the light-sources and detectors, an optical wiring method has been proposed to
enable easy assembly. The key benefit of fiber optic link is the absence of electromagnetic interference (EMI) noise
creation and susceptibility.
This paper provides a method for optical interconnection between an optical Tx and an optical Rx, comprising the
following steps: (i) forming a light source device, an optical detection device, and an optical transmission unit on a
substrate (metal optical bench (MOB)); (ii) preparing a flexible optical transmission-connection medium (optical wiring
link) to optically connect the light source device formed on the substrate with the optical detection device; and (iii)
directly connecting one end of the surface-finished optical transmission connection medium with the light source device
and the other end with the optical detection device. Electronic interconnections have uniquely electronic problems such
as EMI, shorting, and ground loops. Since these problems only arise during transduction (electronics-to-optics or opticsto-
electronics), the purely optical part and optical link(interconnection) is free of these problems. 1
An optical link system constructed with TRx modules was fabricated and the optical characteristics about data links and
EMI levels were measured. The results clearly demonstrate that the use of an optical wiring method can provide robust
and cost-effective assembly for reducing EMI of inter-chip interconnect. We successfully achieved a 4.5 Gb/s data
transmission rate without EMI problems.
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