Accuracy on emitted wavelengths in DFB laser arrays resulting from the longitudinal mode selection mechanism

We compare the merit of various longitudinal mode selection mechanism in di stributed feedback laser for application as arrayed sources in the waveleng th-division multiplexing context. Phase-shifted and complex-coupled laser a rrays have been fabricated and characterized. We propose that the dispersio n on the emitted wavelengths is strongly correlated to the field localizati on along the cavity, By comparison of the dispersion values measured within the laser arrays, we can conclude that the complex grating with gain is th e best suitable mechanism for high wavelength accuracy and stability, due t o the strong and distributed localization of the field in the gain sections of each period of the grating.