An optically powered drive circuit, for controlling the switching operation of a first semiconductor switch coupled between a switch voltage source and a load, wherein the first semiconductor switch has a base node or a gate node, the optically powered drive circuit being adapted to be powered and controlled via a first light signal from a fiber optic cable, the optically powered drive circuit comprising: a photovoltaic cell configured to receive the first light signal from the fiber optic cable and to output a first voltage at a first node relative to a reference node in response to the first light signal; an energy storage device being electrically connected to the photovoltaic cell via a diode and being configured to store electrical energy received from the photovoltaic cell via the first voltage, and to output a second, lower, voltage at a second node; an electrical circuit electrically coupled to the energy storage device, the electrical circuit being energized by the second voltage, and the electrical circuit being electrically coupled to the photovoltaic cell, the electrical circuit being configured to receive the first voltage and to output a third voltage in response to the first voltage for controlling operation of the first semiconductor switch; characterised in that the optically powered drive circuit further comprises: an inductor connected in series between a third node of the electrical circuit and the base node or the gate node of the first semiconductor switch, the inductor forming a resonant gate driver configured to transfer power from the electrical circuit to the first semiconductor switch in response to the first voltage being received by the electrical circuit; wherein the electrical circuit comprises a second semiconductor switch, which is a PNP transistor and is configured to transition the first semiconductor switch to a first operational state in response to the first voltage being received by the electrical circuit, wherein the second semiconductor switch is operable to pass current between the second node and the base node or the gate node via a diode to provide a positive pulse of current to the third node; and wherein the electrical circuit further comprises a third semiconductor switch, which is an NPN transistor and is configured to transition the first semiconductor switch to a second operational state in response to the first voltage not being received by the electrical circuit, wherein the third semiconductor switch is operable to pass current between the reference node and the base node or the gate node via a diode to provide a negative pulse of current to the third node. a photovoltaic cell configured to receive the first light signal from the fiber optic cable and to output a first voltage at a first node relative to a reference node in response to the first light signal; an energy storage device being electrically connected to the photovoltaic cell via a diode and being configured to store electrical energy received from the photovoltaic cell via the first voltage, and to output a second, lower, voltage at a second node; an electrical circuit electrically coupled to the energy storage device, the electrical circuit being energized by the second voltage, and the electrical circuit being electrically coupled to the photovoltaic cell, the electrical circuit being configured to receive the first voltage and to output a third voltage in response to the first voltage for controlling operation of the first semiconductor switch; characterised in that the optically powered drive circuit further comprises: an inductor connected in series between a third node of the electrical circuit and the base node or the gate node of the first semiconductor switch, the inductor forming a resonant gate driver configured to transfer power from the electrical circuit to the first semiconductor switch in response to the first voltage being received by the electrical circuit; wherein the electrical circuit comprises a second semiconductor switch, which is a PNP transistor and is configured to transition the first semiconductor switch to a first operational state in response to the first voltage being received by the electrical circuit, wherein the second semiconductor switch is operable to pass current between the second node and the base node or the gate node via a diode to provide a positive pulse of current to the third node; and wherein the electrical circuit further comprises a third semiconductor switch, which is an NPN transistor and is configured to transition the first semiconductor switch to a second operational state in response to the first voltage not being received by the electrical circuit, wherein the third semiconductor switch is operable to pass current between the reference node and the base node or the gate node via a diode to provide a negative pulse of current to the third node.