Tomographic atom probe comprising an electro-optical generator of high-voltage electrical pulses

A tomographic atom probe having means for applying an electrical evaporation pulse of amplitude Vp and duration Δt0 to an end of a sample which is placed at a potential V0, said tomographic atom probe comprising:

• an electrode which is placed at an initial potential Vi and is configured and arranged to apply the electrical pulse to the sample;
• a voltage generator to produce a voltage necessary for producing a pulse of amplitude Vp, the voltage generator being connected to the electrode by means of an electrical connection which can be open or closed;
• means for causing closure of the electrical connection in a given time τ so as to apply a voltage step Vp to the electrode, these means comprising a chip of semiconductor material placed on the electrical connection between the generator and the electrode, in the vicinity of the electrode, and a first source emitting light pulses of wavelength λ1 to the semiconductor chip, said chip becoming conductive and closing the electrical connection when it is illuminated with a light pulse of wavelength λ1, the conduction time being a function of the duration of the light pulse applied;
• means for applying a voltage step of amplitude (−Vp) to the electrode at the end of a time Δt0 after closure of the electrical connection, so as to place the electrode at the potential Vi, said means being configured so that the voltage step is applied in a time τ′ substantially equal to τ.