Radiation hardness studies of VCSELs and PINs for the opto-links of the Atlas SemiConductor Tracker

We study the radiation hardness of the Vertical Cavity Surface Emitting Laser diodes (VCSELs) and the epitaxial silicon PIN diodes that will be used for the Atlas SemiConductor Tracker at the CERN Large Hadron Collider. The tests were conducted with 200 MeV protons to a fluence of 4×1014p/cm2 and with 20 MeV (average energy) neutrons to 7.7×1014n/cm2. The radiation damage of the VCSELs and PINs and the annealing characteristics are presented.