An object is to provide a semiconductor device having a novel structure, which can hold stored data even when not powered and which has an unlimited number of write cycles. Orthogonal frequency division multiplexing symbols of the data portion are generated using one of a normal guard interval, a short guard interval and a long guard interval. The power module is characterized in that an inductance component of at least one of the first and second connection means is adjusted so that the inductance component between the emitter electrode on the first power device and the emitter lead is substantially equal to that between the emitter electrode on the second power device and the emitter lead. The electrical predistorted signal is then used to modulate an optical source to generate a corresponding predistorted optical signal for transmission through the optical link.