Multiwavelength semiconductor laser source for dense wavelength division multiplexing (DWDM) applications based on a novel dispersive cavity is described. Multiline lasing on the basis of a single-diode laser chip and multi-stripe diode laser is analyzed theoretically and demonstrated experimentally. Simultaneous lasing across ∼80% of the FWHM of the luminescence bandwidth of the AlGaAs active medium (657-667 nm) in multiline regime with a special pre-assigned spectral composition was realized. For DWDM applications a prototype of this superbroadband semiconductor laser operating in one of the telecommunication wavelength bands around 1.5 μm has been designed on the basis of a multi-stripe diode chip. Simultaneous lasing of four spectral lines in the region 1567-1577 nm has been obtained. © 2003 Elsevier Science B.V. All rights reserved.