An integrated 4 x 4-channel multiwavelength laser on InP

We present a compact 16-channel digitally tunable laser integrated on InP with the possibility to produce groups of four wavelengths at the same time. The cavity contains two arrays of four semiconductor optical amplifiers (SOAs) with two periodical four-channel intracavity phased arrays (PHASARs) with channel spacings of 100 and 400 GHz. By activating two out of the eight SOAs, 16 different wavelengths can be selected. Light was coupled out of the cavity by waveguides placed in the second focal order of the PHASARs. Reflections from the end facets of the wafer are minimized using mode filters and angled output waveguides.