Numerical physics of subpicosecond electrical pulse generation by nonuniform gap illumination

The physical mechanism of subpicosecond electrical pulse generated by nonuniform illumination of transmission-line gaps is studied in detail using a two-dimensional numerical model. This model agrees very well with existing theories as well as experimental observations and further explains the observed highly nonuniform field distributions, which have been neglected in previous theories. The pulse dependence on light intensity, bias voltage, substrate doping, and beam size and location are studied and discussed. It also confirms that this mechanism should be observable in silicon.