Radiation-Hardened Parallel VCSEL Laser Driver for High Energy Physics

Future particle physics experiments at the high-energy frontier, such as LHC, HL-LHC, ILC, CLIC or Multi-TeV Muon Collider, will all require silicon detectors capable of reconstructing charged particle trajectories with high accuracy in the presence of significant high occupancy. These experiments will impose stringent demands on the data links to transfer the data from the silicon detector to the data acquisition system, either just for readout purposes or for triggering purposes, or both. The large amounts of data required from silicon detectors in these experiments require large parallel or very high- speed serial data links. A promising approach being investigated for producing high-data- rate links are miniaturized parallel optical links. There are a number of challenges specific to next generation high-energy physics applications that must be overcome, including radiation hardening, temperature dependence, and low power consumption. Southern Methodist University has designed and demonstrated a 4-channel, 8-Gbps-per- channel, radiation-tolerant VCSEL laser driver fabricated in a commercial 0.25-m Silicon-on-Sapphire SOS) CMOS technology which is scalable to 12 channels. VCSEL laser drivers may also be useful for driving electro-optic and electro-absorption modulators. To improve both speed and radiation tolerance, it is necessary to move the design to 65nm CMOS technology. Vega Wave Systems and Southern Methodist University will work together to design, fabricate and test 10-Gbps-per-channel, radiation-tolerant VCSEL laser drivers fabricated in 65nm CMOS for use in high speed parallel optical links for high-energy physics applications. The development of this radiation-hardened high speed laser driver IC will greatly benefit the High Energy Physics and Nuclear Energy communities by improving the performance of high speed fiber optic links for use in high radiation environments as comparable commercial ICs are not radiation-tolerant.