Ten-channel optical transmitter module for sub-system interconnection operating at λ=1.3 μm up to 12.5 Gbit/s

Parallel optical interconnection devices feature wide bandwidth, low loss and cross-talk, small size and weight along with low power consumption and cost. They appear particularly suitable to replace the electrical interconnections wherever high connection density and transmission capacity are required (e.g., in board-, cabinet-, and building interconnections). We report on a 10-channel parallel optical transmitter module with a 12.5 Gbit/s total bit-rate. The module includes a commercial 10-channel Fabry-Perot laser array chip) emitting at λ=1.3 μm, coupled to a standard 50/125 μm multimode fiber ribbon, and a silicon CMOS laser driver IC. The IC allows low power consumption even at the high bit-rate achieved, and therefore requires only a passive thermal management, contributing to lower the costs. The output optical power of both logicall 0 and 1 levels can be adjusted externally. The module operates up to 1.25 Gbit/s/ch, exhibiting at a bit error ratio (BER) better than 10^-14. With a power budget of more than 10 dB and a power consumption of 130 mW per channel. An interconnection distance in excess of 1200 m has been demonstrated, with a residual power margin of 4 dB without BER degradation. In this way our transmitter gives interconnection distances in excess of 500 m, not attainable with the shorter wavelengths given by surface emitters, and permits low power dissipation (low threshold light source and CMOS circuits) and low cost fabrication. Such characteristics make the module interesting for applications in which medium-long distances are involved and high bit-rates required, but reduced power consumption and dimensions are mandatory, as for interconnections between submodules in the large switching nodes of new generation