120 Gb/s VCSEL-based parallel optical link and custom 120 Gb/s testing station

Abstract

A 120Gb/s optical link (12 channels at 10 Gb/s/ch) has been demonstrated. The link operated at a BER of less than 10 -12 with all channels operating and with a total fiber length of 316 m which comprises 300m of next generation (OM-3) multimode fiber (MMF) plus 16m of standard grade MMF. This is the first time that a parallel link with this bandwidth at this per channel rate has ever been demonstrated. For the transmitter, a SiGe laser driver was combined with a GaAs VCSEL array. For the receiver, the signal from a GaAs photodiode array was amplified by a 12 channel SiGe receiver IC. Key to the demonstration is the use of several custom testing tools, most notably a 12-channel pattern generator. The package is very similar to the commercial parallel modules that are available today, but the per-channel bit rate is three times higher than for the commercial modules. The new modules demonstrate the possibility of extending the parallel optical module technology that is available today into a distance*bandwidth regime that is unattainable for copper cables.