38 GHz optical harmonic mixer for millimetre-wave radiowave systems

The optical harmonic mixing capability of a high speed 1.5 µm DFB laser is demonstrated at 38 GHz. A 700 Mbit/s digital NPZ signal combined with a 9.5 GHz local oscillator modulates the laser and upconverts the frequency to 38 GHz. A bit error rate (BER) of 10-9 after IF amplification is obtained with –18 dBm at 700 Mbit/s for a received DC optical power of 0.6 dBm. The sensivity at 38 GHz for the carrier is –46.5 dBm.