Simultaneous WDM and broadcast transmission using a single multiwavelength waveguide-grating-router laser

We have demonstrated a new technique for simultaneously transmitting multiple WDM channels and broad-band broadcast services using a single multiwavelength waveguide-grating-router laser. Four 150 Mb/s WDM channels, spaced by 1.6 nm, were formed by modulating four gain sections on an 8-wavelength waveguide-grating-router laser. A broadcast service, consisting of 79 MPEG video channels multiplexed into 16 QPSK subcarriers, was simultaneously added to each WDM carrier by modulating the laser's common gain section. To eliminate degradations in video quality due to clipping distortion during baseband zeros, baseband extinction ratios for the four WDM channels were kept in the 55% to 58% range.