Abstract: An optical floating deck modulator to modulate a control element of an electron device, such as the grid of a Klystron tube or traveling wave tube, having two high power MOSFET switching devices connected in series between a high positive and a high negative voltage source (which also supply the high voltage to the electron device) with the control element coupled between the MOSFET devices. This arrangement provides a low resistance path between the two voltage potentials and the control element being modulated, as the two MOSFET devices are switched alternately ON and OFF and thus achieves fast rise and fall times over a very high voltage swing. Each MOSFET device has a separate drive circuit (deck) and each deck comprises a photo diode information receiver coupled to a transimpedance amplifier, the output of which is amplified by a bipolar transistor amplifier and a FET amplifier. Total isolation between the decks and the information source is achieved by an optic link therebetween.