Self-adaptive thin-film electromagnetic shielding screen

An optically transparent self-adaptive electromagnetic shielding device for a lens or for a window of a piece of equipment provided with an electrically conductive enclosure containing an optical or RF sensor behind said lens or said window, said shielding device comprising, on at least one face of said lens or said window, a shielding screen comprising a switchable RF shielding mesh at least partially surrounded by a border of insulator-metal transition material arranged between said mesh and an electrically conductive envelope for shielding said piece of equipment, said shielding device further comprising a susceptor element, arranged facing or in contact with said insulator-metal transition material and adapted to transform incident electromagnetic energy into an amount of activation heat for said insulator-metal transition material, said susceptor element being dimensioned to cause a transition to a conductive state of said insulator-metal transition material under the action of said electromagnetic energy so as to electrically connect, at low impedance, said mesh to said electrically conductive envelope when the incident electromagnetic energy exceeds a predetermined threshold.