The purpose of failure analysis is to locate the source of a defect in order to characterize it, using different techniques (laser stim- ulation, light emission, electromagnetic emission...). Moreover, the aim of vulnerability analysis, and particularly side-channel analysis, is to ob- serve and collect various leakages information of an integrated circuit (power consumption, electromagnetic emission ...) in order to extract sensitive data. Although these two activities appear to be distincted, they have in common the observation and extraction of information about a circuit behavior. The purpose of this paper is to explain how and why these activities should be combined. Firstly it is shown that the leak- age due to the light emitted during normal operation of a CMOS circuit can be used to set up an attack based on the DPA/DEMA technique. Then a second method based on laser stimulation is presented, improv- ing the “traditional” attacks by injecting a photocurrent, which results in a punctual increase of the power consumption of a circuit. These tech- niques are demonstrated on an FPGA device.