Experimental Characterization of a MMW Signal Generation Approach Based on Optical Phase Modulation and Optical Filtering for Data Transmission over a Directly Modulated Laser

In this paper, we present a detailed characterization of a phase modulation (PM)-based approach employing optical filtering for photonic millimeter wave (mmW) signal generation. Simulations and experimental results exhibit a very good agreement showing that both the bandwidth and the notch peak of the optical filter lead to the overall system response up to 15 dB electrical gain in the mmW band, also due to the combination of laser chirp and 10 km fiber dispersion. The system error-vector-magnitude (EVM) performance for a 25 MHz bandwidth QPSK signal is characterized for a large range of electrical mmW power values over different frequencies while intermodulation distortion is found for high power levels. Accordingly, in the linear regime, it is observed than 10 km SSMF link leads to improved EVM values compared to OB2B in terms of RoP, while measurements performed for different ReP values show the transparency of this approach with no further degradation with respect to EB2B tests. Therefore, this method is confirmed as very promising for future deployment of mmW-based communication networks using photonic technologies for signals generation and transmission.