A LED tube includes a translucent or fluorescent tube of substantially the shape and size of a fluorescence tube, inside which one or more LED components and a current control unit are installed. At both ends of the LED tube, there is a pair of contact pins for connecting the light element mechanically and electrically to the tube holders of the fluorescence tube lighting fixture. The tube lamp has a safety unit arranged to prevent a voltage from transferring through the tube lamp from its one end to the other until a voltage supplied from the corresponding tube holder of the lighting fixture to the pair of contact pins has been separately detected at each end of the tube lamp. Inside the LED tube, there is at least one optical line that is arranged to transfer a control or measurement signal associated with the safety unit from one end of the LED tube to the other without capacitive leakage currents.