Description is given of a high-resolved optical multichannel analyzer (OMA) system and of a firing set whereby Oh?A records and electrical measurements from a single discharge of a semiconductor bridge (SCB) may be accurately correlated in time. Such a correlation obtained by the novel experimental system is used in order to explain the dynamic discharge behaviors, especially the plasma formation, of the bridges. From the results of the experiments, the minimum electric field to generate a plasma from the W-land SCB is about 0.77 x 10(3) V/cm and the time required to evolve the plasma from the bridge is about 1.5 mu s, for the SCB 47 mu m long and 140 mu m wide.