High single-mode-yield multiple-wavelength DFB-laser arrays in the 1.55 m range

Based on a DFB grating design we have developed a four wavelength laser array with excellent single mode operation and high power output. We could routinely stabilize a high level of single laser yield of about 90 % and hence, array yields better than 60 %. This was accomplished by a precise control of phase-shifted index gratings with kL=1.5. To use the advantage of higher grating feedback with kL > 1.5 the single mode yield was improved by a tailored phase shift design.