High bit-rate 10 channel optical transmitter for sub-system interconnection

Abstract

Parallel optical interconnections allow for a substantial improvement in the capacity of systems associating an high bit-rate for each channel with a consistent reduction in the number of cables needed for interconnecting different system parts, such as boards or cabinets. We constructed a 10 channel parallel optical transmitter with 12.5 Gbit/s total bit-rate. The silicon CMOS (Complementary Metal Oxide Semiconductor) laser driver Integrated Circuit (IC), completely designed in CSELT, allows for low power consumption and low-cost even at the high bit-rate achieved with this device. The module as a metal package pigtailed with a 50/125 mm fibre ribbon with standard MPO/sup TM//MTP/sup TM/ push-pull multifibre connector. The laser array is a low threshold edge emitting Fabry-Perot commercial device with /spl lambda/=1.3 /spl mu/m, which makes it suitable for the fibres used in the telecom networks. During thorough lab tests the module has been operated up to 1.25 Gbit/s/ch with a good performance in terms of BER (Bit Error Ratio) characteristic, better than 10/sup 14/, with a power budget of more than 10 dB and an overall power consumption of 1.3 W. The interconnection distance has been proven to be more than 500 m with a residual power margin of 4 dB with satisfactory BER figures.