Five-wavelength integrated DFB laser arrays with quarter-wave-shifted structures

Five-wavelength integrated DFB laser arrays with quarter-wave-shifted structures, using nonuniform stripe width, have been developed for high-density WDM systems around the 1.3 μm wavelength region for the first time. Each DFB laser of the five-wavelength integrated DFB laser array oscillated at the Bragg wavelength with a side mode suppression ratio of more than 30 dB. Good reproducibility of 50 ± 5 A lasing wavelength separations has been obtained.