A novel photonic generation of power-efficient ultra-wideband (UWB) pulse by combining two asymmetric monocycle pulses with inverted polarities is experimentally demonstrated. The principle lies in cross-phase modulation (XPM) in a single semiconductor optical amplifier (SOA) and phase modulation to intensity modulation conversions in an arrayed-waveguide grating (AWG). The Federal Communications Committee (FCC) compliant UWB pulse gains 24.3 dB and 20.8 dB improvements compared to positive and negative monocycle pulses after power attenuation to respect the FCC spectral mask, respectively. The generated power-efficient UWB with pulse duration of about 310 ps has potential to achieve high speed transmission and modulation without overlapping and distortion.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.