In order to carry out high-speed packet communications using a large-volume transmission channel like an E-DCH, uplink communication quality must be good. The fundamental laser light is reflected by a flat mirror and amplified again passing through a Q-switch, a solid-state laser medium, a Q-switch, a Q-switch, a solid-state laser medium, and a Q-switch. In addition, the identifying element transmits the fundamental frequency of the oscillating fork to the control input of a frequency evaluation circuit, the input of which is connected to the output of the oscillator circuit. The current sensing unit is operably coupled to generate a sensing signal that is dependent on the current in the load path.