Three-dimensional mapping of single-event effects using two photon absorption

Carrier generation based on subbandgap two-photon absorption is used to perform three-dimensional mapping of the single-event transient response of the LM124 operational amplifier. Three classes of single-event-induced transients are observed for the input transistor Q20. A combination of experiment and transistor level modeling is used to assign the different classes of measured transients to charge collection across specific junctions. The large-amplitude, positive-going transients cannot be assigned to a single junction, and are identified with a collector-substrate photocurrent.