Radiation Hard Optical Link Developments at CERN

Abstract

The Versatile Link project at CERN has developed a radiation tolerant transceiver module, so called Versatile Transceiver, for the uniquely harsh environment inside high energy physics experiments, where optical and electrical components have to withstand extremely high doses of both particle and ionizing radiation. Rigorous evaluation of candidate components has been carried out during the development phase and now we have entered into the production phase with the selected components. We are producing around 40 000 radiation tolerant transceivers, all of which go through an extensive quality assurance process. The functionality has been tested in laboratory conditions and across a wide temperature range, as well as the reliability of the assembly has been verified in accelerated aging tests. One of the most important parts of the quality assurance is to verify the desired radiation hardness. Samples from all photodiode and laser wafers used in the Versatile Transceiver production were exposed to both gamma rays and neutron fluence. Fully functioning final modules were tested in a complex test setup which enabled us to test all main transmitter and receiver parameters during the irradiation. Samples, both optical components and full modules, experienced the expected degradation in performance but the transceiver modules were able to transmit error free data with required margins even in the end of the irradiation.